Marnix Everaert

Solanum Africanum - 2007

Screenprint - series of 8 - +/- 5.8" H x 4.1” W

  www.marnix-everaert.be

Silkscreen offers the broadest spectrum of printing applications, and it facilitates printing on all kinds of paper as well as on a wide variety of unusual substrates, such as plastics, wood, or metal. The medium seamlessly combines the expressive vocabulary of the artist’s hand made gesture with the world of the reproduced image, and full color printing. Three decades ago the print quality of the water based process was not always on a par with the (much more toxic) oil based process. 

These obstacles have been overcome through improvements in the water based inks, pigments, dyes, and mediums. Even the master of Pop Robert Rauschenberg used the water based process in the creation of his recent silkscreened assemblages, such as his monumental ‘1/4 mile Piece’ documented in ‘Man at Work’.

Following some very straightforward instructions almost anybody can set up a safe and simple screenprinting facility in their garage or spare bedroom. Many successful printing firms and artist print studios were started this way - Andy Warhol's factory was one of them. With the addition of an etching press the range of possibilities can easily be extended to include the new Intaglio Type medium as well, and many workshops now have UV or halogen exposure systems that cater for both photopolymer based processes.

'tulip 2', 2010, Michael Hitchens, based in Manchester, England. The majority of his work presently revolves around water-based screen printing using digital artwork and CMYK printing. 

Joe Lindsey

Silkscreen and Digital Print

Columbia College Chicago

Academic Print Studio

2007

Nintendo Half Tube

Silkscreen and Digital Print

Installation on wooden Half Tube

Chester University

   Silkscreen: Basic Process Instructions 
      (Blick online)

   Safety of Acrylics and 
           The Art of Polymer Paints

contrary to popular opinion, 

acrylics are not considered 'nontoxic' 

(from: A pilot study to evaluate VOCs outgassed in polymer filaments, Shari Cheves, 2014)

Inherent Instability in Monomers and Polymers

"Plastic polymers are created from monomers almost exclusively derived from crude oil with far-reaching impacts on the health of humans and the environment. These highly reactive monomers form stable bonds in polymers through polymerization, though the chemical reactions are never quite complete. This inherent instability contributes to the release of residual monomers, plasticizers, ame retardants, solvents, and other additives as polymers degrade. 

Based on the toxicity of monomers, research has defined the most hazardous polymer families as polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. Monomers and other by-products are released through various modes of degradation such as heat. Nitrogen-containing plastics such as nylon and polyurethanes typically release hydrogen cyanide; chlorine-containing materials such as polyvinyl chloride typically release hydrogen chloride; and polystyrene, polyesters such as polycarbonate, nylons, and polyurethanes may be more likely to degrade into their original monomers."

Most manufacturers of acrylic artist paints offer a dedicated medium or paste which is mixed with their artist acrylics to obtain a printing ink. Acrylics by themselves are too fast drying and too viscous to make serviceable printing inks. The dedicated silkscreen printing mediums contain thickeners and retarders that make acrylics printable. Most systems have a 50% to 50% recommended ratio between ink and medium to obtain a good ink. In practice, the addition of these mediums has little effect on the luminosity and opacity of the acrylic paint. In essence these systems provide an opportunity to create printed marks on paper using high quality artist paints rather than commercial printing inks, which are often lacking in light fastness and color quality. 

For thinner washes and translucency, inks can be thinned through further addition of printing medium, extender base, or water. Although manufacturers recommend staying within their own product lines, the different types of acrylic paint, modifiers and mediums can easily be intermixed by the artist or printer to obtained desired properties. Once you've mixed a batch of ink with a plastic kitchen spatula store it in lidded plastic containers and keep color swatches to be able to identify the correct hues. The acrylic silkscreen ink, once mixed, can be stored for several years without deterioration.

 

50% Acrylic Paint + 50% Printing Medium = Acrylic Screenprinting Ink

 

Rowney System3 Printing Medium   /   Lascaux Silkscreen Paste   /   Golden Silkscreen Medium

 

There is a wide variety of acrylic printing mediums and modifiers that allow for further refinement of the inks, through the addition of gloss medium, thickener, texturing agents, and so on. The range of acrylic paints, ready-made inks, and modifiers available today make it easy to obtain the luminous and highly opaque ink deposits that were once only possible in the oil based process. At the same time, the water-based process also facilitates the opposite to the opaque graphic surfaces of Pop art: delicate wash work, textures, and translucency that is typical of media such as water color and lithography. Two of the pioneers of the water-based method - Roni Henning, and Carol Robertson - demonstrate the medium’s potential for extremely detailed and delicate work in their editioning practice.

ULANO

This harsh chemical environment is known for its potential to be particularly harmful to the printer and the artist. There are numerous known cases of neurological disorders, cancer, Asthma, and respiratory illness that are believed to have originated in oil based silkscreen practice. 

Problems can be exacerbated by the fact that many printers do not wear respirators while handling and inhaling neurotoxic fumes, and often extraction systems suffer from poor designs (powerful local extraction is the best solution available. Such as: Nederman Gas Cart). Since the 1960s there has been increasing medical evidence that most petroleum derived solvents are toxic. This has been the basis of various lawsuits brought by afflicted workers (in the US railway industry, for example). Over the past 20 years - and with little publicity - there have also been lawsuits regarding sickness or injury resulting from solvent use at art schools. (See Artmaking and The Law).

the UK firm Natgraph makes excellent UV exposure systems using metal halide light sources. As opposed to other systems these type of top loading machines can handle both photo silkscreens as well as photo-polymer intaglio plates. This saves expense and floor space.

Screen printing four layers on a hand bench

A screen is made of a piece of mesh stretched over a frame. The mesh could be made of a synthetic polymer, such as nylon, and a finer and smaller aperture for the mesh would be utilized for a design that requires a higher and more delicate degree of detail. For the mesh to be effective, it must be mounted on a frame and it must be under tension. The frame which holds the mesh could be made of diverse materials, such as wood or aluminum, depending on the sophistication of the machine or the artisan procedure. The tension of the mesh may be checked by using a tensiometer; a common unit for the measurement of the tension of the mesh is Newton per centimeter (N/cm).

(Wikipedia illustration)

A pressure washer is used to remove old paint from a boat.

Pressure washing or power washing is the use of high-pressure water spray to remove loose paint, mold, grime, dust, mud, chewing gum and dirt from surfaces and objects such as buildings, vehicles and concrete (Wikipedia)

    Safer Solvents

silkscreen installations (F.K.), Gallery Daeppen, Basel

 

Screenprinting the complete water-based system

Carol Robertson / Robert Adam, Thames and Hudson

With clear step-by-step instructions and over 250 illustrations—most in full color—this is a definitive guide to fine-art water-based screenprinting.

Screenprinting has never been so popular—and the water-based process is the best way to do it. This practical and inspirational resource book explains and describes methods and materials that replace traditional toxic screenprinting systems. It is the modern option: safer, healthier, and more environmentally friendly, as well as quick to learn and accessible to all. 

Whether you wish to print using photo stencils, paper stencils, or screen filler stencils, with opaque, translucent, metallic, pearlescent, or iridescent paints, on delicate Japanese paper, handmade bark paper, fabric, metal, or PVC, renowned practitioners and art educators Robert Adam and Carol Robertson show you how to do it. 

The book covers every stage of the printing process and opens up new areas of creative possibilities, whether printing small editions or works for large-scale installations. From choosing which materials to use and how to use them, through setting up and equipping your own water-based screenprinting studio, to collating and presenting your finished prints, this comprehensive reference book—complete with glossary and list of international suppliers—is the only resource you'll ever need. 265 illustrations, 228 in color. Robert Adam and Carol Robertson worked for nine years at the renowned Edinburgh Printmakers Workshop. They now operate their own studio, Graal Press, and teach printmaking at the Wimbledon School of Art. Together with Friedhard Kiekeben they helped pioneer the European variant of acrylic resist etching in the early 1990s.

(Wikipedia illustration)

A. Ink. B. Squeegee. C. Image. D. Photo-emulsion. E. Screen. F. Printed image.

 

  Screenprinting Solutions

I have been a printmaker (primarily screenprinting) 

for over thirty years, 

making fine art editions for artists, 

both emerging and well known. 

Among those artists were Agnes Martin, Romare Bearden, 

Jack Youngerman, Alice Neel, Andy Warhol, 

Red Grooms and Larry Zox.  

Eighteen of those years were spent at The New York Institute Of Technology's Screenprint Workshop as their masterprinter-in-residence. The Workshop was a unique facility that allowed artists to make limited editions of their art in collaboration with the masterprinter. It also permitted the students to have an opportunity to watch prints being made professionally by established and prominent artists. In that way it functioned as a teaching facility. I also taught the screenprinting, etching and design classes at the college. 

At that time the Screenprint Workshop was a solvent-based facility with oil-based inks and naphtha and acetone as the cleaning materials. Although there were fans there was no exhaust system to remove the bad air and replace it with fresh. Such a system was very costly and the college couldn't afford it. It was after completing a forty color edition of 600 prints that I started to question what I was doing to myself, the environment and my students. 

Printers are a rigid breed and once they have developed a system of printing that works well, they are reluctant to change. I myself had felt this reluctance. I didn't realize that if something is poisoning you and the environment it can hardly be considered to be working well, even though the product looks good. Once, when I was working for another print studio in New York City, and I was traveling home on the subway, I overheard two people commenting on how they thought they were painting the subway cars. But I knew it was only me, my clothes smelled of silkscreen ink. 

There were water-based inks out there at this time that were used for crafts in the schools but they had a limited, poor color range and because of the water content they also buckled the paper. Some art colleges were using a toner and transparent base system but none of that was professional enough for the artists and galleries that I worked with. I was a printer that was used to mixing colors from gallons of opaque ink with a large diverse palette. I could then add transparent base if need be, but I would also have the opacity if that were what the print required. So I started to look around for options.  

  

  Screenprinting Solutions

   

TW Graphics is a silkscreen supplier located in California. They were recommended to me by a fellow printmaker. They offered a line of opaque water-based inks that they claimed was comparable to their oil-based line. So between 1985-86 I tested and printed with their 1000 series. It's one thing to print your own art work and maybe accept some imperfection but not when you are editioning for other artists and major publishers like Pace Gallery. So it took time to get the results that I needed. 

There were problems; particularly with ink not drying thoroughly and having prints stick together when they were stacked. When working with water-based inks you have to change your methods. Everything has to be blocked out from the inside of the screen not the back. The emulsion must be resistant to water but able to be reclaimed.  

When you pull the squeegee across the screen it isn't as fluid as oil-based ink. All of those issues had to be dealt with. Today those inks have been reformulated and the sticking problems solved. Even the slippery quality of the ink is better. There are other manufacturers like Speedball who have greatly improved their water-based acrylic inks. There are also a few other companies like Standard inks in New York that will give you a good professional result. Createx inks work with a base and toner system and the color range is very good. Even though there is nothing comparable to oil-based fast dry enamel and lacquer inks there is enough variety in the water-based line to make any health and environmentally concerned person switch. Every artist that I work with tells me how wonderful it is to work in a toxic free print shop.

The reason I wrote my first book, Screenprinting Water-Based Techniques, was to showcase the creative, high quality prints that were made with water-based inks and to assist serious printers and artists in their transition from an oil-based system.

When I was experimenting with perfecting my printing techniques with the water-based inks I started playing with other watersoluble materials to see if I could print them through the screen. That's how I started making monotypes with a screen. First I tried various watersoluble crayons and pencils but soon discovered how to use watercolor and gouache to create unique monotypes and monoprints. My second book published by Watson-Guptill, Water-Based Screenprinting Today, devotes a chapter to making a monotype, or monoprint with a screen, and showcases a variety of prints made by other artists working with me.   

Making a Screened 
Watercolor Monotype

A monotype or monoprint is simply a painting that is made using a printing process. Traditionally they are made using an etching or litho press. The distinction between the two is determined by how the artist begins. A monotype begins with a blank stretched screen and a monoprint starts with an image or stencil already on the screen. The instructions below are for making a monotype.

Begin the process with a screen stretched with a white 195-230 mesh monofilament fabric. A higher number will give you a finer mesh and image, and a lower number will give you a slightly coarser mesh and image but heavier deposit of color.

Block out the area of the screen that you don't want to print, leaving only the opening that you want the color to pass through.  

The simplest method for blocking out a screen is to draw an opening (square or rectangle etc.) with a pencil and ruler on the inside of the screen. Then apply wide transparent packing tape on the outside of the lines to create the opening. This thin, tacky tape adheres securely and doesn't come off with the pull of the squeegee.  

Cover the rest of the exposed screen to the edges with clear contact (shelf) paper, available at any hardware store. This leaves only the area to be printed open. There are more permanent methods of making an open area on the screen with screen filler or photographic emulsion, but I find that the taped screen is fast and efficient. It's especially useful for the artist that likes to change the size of the opening without having to clean off a permanent stencil.

Once the screen is prepared you can begin the painting process. Each artist approaches a monotype differently. You can paint or draw directly onto the screen just as you would onto paper or canvas, or you can rely on a matrix. This gives you something to work from like a photo or drawing.



Painting The Screen
Screens can be painted anywhere, not just on a printing table. I used to take a screen outside in my garden to paint it.  All you need is a table or flat board on which to prop the screen. Raise it slightly off the surface so the paint doesn't go through. Then begin.  

Any brand of watercolor or gouache will work. Some just work better than others, usually the cheaper brands that have less pigment. Watercolor will release from the screen more easily than gouache which is denser and tends to resist in the screen. This quality gives the monotype an unpredictable result. Experiment with various paints and techniques to develop a more informed idea of how to get the desired results. 

If you paint too thickly or one color on top of another, it could cause the colors to resist so only the edges of the painted areas print. You may like these effects, otherwise print in multiple steps if you want to layer colors. The pigment concentrations in different brands also produce varying results. Dry the paint with a hair dryer before printing to prevent it from smearing.

A silk screen design

(Wikipedia illustration)

https://en.wikipedia.org/wiki/Screen_printing

Printing The Screen
All you need to print the monotype is a table, or a board with hinge clamps to attach the screen. Hinge clamps can be purchased at most art or silkscreen supply stores. There is no need for expensive printing equipment. You print monotypes and monoprints with transparent water-based screenprinting base. TW Graphics, Standard, Speedball and Createx are some of the suppliers. You can also get Speedball at Dick Blick.  

Although you can print on any paper or surface I like 100% cotton rag paper, such as Arches cover, Arches 88, Rives BFK, Somerset, or Stonehenge. The smoother, harder paper like Stonehenge is a good choice when printing detail or pencil and charcoal drawings.  

Fasten the prepared screen into the hinge clamps. Hold the front of the screen up with a small block of wood. Mix 10 - 15% retarder into the transparent base to retard the drying time and help the watercolor release from the screen. Two good retarders are Golden Acrylic and Propylene Glycol. Align the paper under the screen and mark its position with registration guides like small pieces of cardboard or masking tape. Place two on the front of the paper in front of the screen and one on the right side.  Tape the paper down if you are not using a vacuum table. This will allow you to print more than once without the paper moving.  You use a squeegee to flood the screen, that means pushing the base across the image while the screen is up. That re-wets the painted area. Flood the screen back and forth 2 or 3 times until you see the color start to dissolve and show on the squeegee's blade.  

Remove the block of wood and lower the screen directly onto the paper. Keep the squeegee at a 45-degree angle and pull it across the image.  Always end your flood stroke away from you so you can print by pulling the squeegee toward you with even pressure. Lift the screen and examine the print. If it is too light and not enough printed you can either flood and print again or you can print on a second sheet of paper.  That would give you two prints that you could print on again when you repaint the screen. Sometimes you can get 4 or 5 lighter versions (called ghost images) like that, to print over in a variation of the original colors and create a series. Whenever you pull the squeegee across the image make sure that you don't reflood with base that is full of color. That will cause streaks on the next printing. Scrape that base off and pour fresh base in the screen. You can use the tinted base to add to silkscreen ink to make it transparent. Don't discard it.

The printing process adds its own dimension to the character of an image, different from a direct drawing or painting. That is why artists love monotypes and monoprints. There is always the element of surprise after you print and look at the image. Experiment with drawing and painting techniques. Try painting thickly and thinly or wetting the screen and then painting. Once you get used to painting on the screen add watersoluble crayons. Next try graphite pencil and charcoal. Even though they are not watersoluble the pressure of the squeegee forces them through the screen onto the paper.

Once you are finished printing, scrape all the base out of the screen and remove the tape and contact paper. If you have a sink that is big enough for your screen you can wash it there with a good hose. Otherwise you can wash the screen on the table with a sponge, paper towels, and a container of water.  It's so much more pleasant than the old days with solvents. I used to dread cleaning the screen with naphtha. If the watercolor and gouache is hard to remove with water just use simple green or any detergent and a scrub brush to remove the stubborn spots. RH

   

HENNING SCREENPRINT WORKSHOP

Roni Henning is available for contract printing specializing in Monotypes and Monoprints and consultations for converting to non-toxic screenprinting.

Water-based Screenprinting weekend workshops are held monthly at her studio and one-day tutorials upon request.  Check the website for dates and times.

In addition to teaching at her studio Henning teaches on an on going basis at The Lower East Side Print shop in NYC.  

Roni Henning's latest book  
Water-Based Screenprinting Today 
published by Watson-Guptill is also available at amazon.com

Editorial: Master printer Roni Henning has embraced water-based screenprinting for its benefits to both the environment and her personal health. In this insightful guide, she has gathered the works, techniques, and experiences of many of the talented artists and printers with whom she has crossed paths during her own illustrious career, printing editions with the likes of Romare Bearden, Andy Warhol, and Jack Youngerman. 

Through the work of Bearden, Youngerman, and Gene Davis, among other top artists, you are guided through the traditional screenprinting process, from building and stretching a screen to color separations, color mixing, proofing, and printing. Henning discusses advances in techniques and process since the rise of water-based screenprinting, the collaborative relationship between artist and printer, and monoprints and monotypes as art forms. Finally, the use of computers and image manipulation software to complement screenprinting is also investigated.

Contact Roni Henning:
Email        roniprint@aol.com
Website    www.ronihenning.com
Phone       917-841-5704

watch an introductory video on Roni's nontoxic printing process on her home page:

http://ronihenning.com/home/

back to             
TOP     |     CONTENT

Since 1991, Steve Walters (under the moniker Screwball Press) has been printing posters, CD packaging, and a variety of other collectible items for Chicago's indie rock community. Over the years, he has had the opportunity to train and/or work with some of his favorite local artists including Bob Hartzell, Kristen Thiele, Jay Ryan, Mike Benedetto, Keith Herzik, and Jason Frederick. Around 2000, Steve looked back on ten years of work and realized that working with these people was the single most satisfying aspect of Screwball Press. So he began to implement the Screwball Academy based on the extension of the Minutemen's "band in every garage" credo. Steve wanted to see a printer in every band. 

At present, Steve has taught 36 people over the past 18 months, most of whom still use the facilities to print personal projects as well as a few who run their own printing businesses.

THE DEAL

Screenprinting is a physical, hands-on process and so is the course. Students come in with a piece (or 2) of black and white line art and leave with up to 50 3-color, 11"x17" prints that they produced themselves. This can be done in a single 6-8 hour session or can be broken up into two shorter sessions. After that, you are free to come back whenever you want to use the facilities.

To schedule a class, email Steve at steve@screwballpress.com

SILK SCREEN PRINTING 


             By Ronald Fuchs and Michael McCann, Ph.D., C.I.H.
                     http://www.uic.edu/sph/glakes/harts1/HARTS_library/silkscrn.txt


     UIC   Health in The Arts Library


 Silk screen printing is one of the most hazardous processes in

the arts and crafts.  Dermatitis, narcosis (dizziness, light-

headedness, fatigue, nausea, lack of coordination and headaches),

eye irritation, adverse reproductive hazards including increased

risk of miscarriage, and serious neurological problems can all

result from the processes of screen printing.  


Traditionally, silk screen printing has been performed using organic solvent-

based materials.  Water-based inks containing less hazardous

ingredients provide a safer and increasingly popular alternative.



SOLVENT-BASED SILK SCREEN PRINTING



Hazards

   The major hazard in silk screen printing comes from

exposure to the solvents in the inks, thinners, clean-up

materials, etc.  Thinners such as lacquer thinner and are a

mixture of these and other hazardous solvents.  The greatest

hazard is exposure through inhalation, causing narcosis

(dizziness, headache, nausea and light-headedness) from acute

exposures, and skin, liver, kidney, reproductive and nervous

system damage with repeated exposure.  Skin absorption can also

produce these effects.  It is also important to note that most of

these solvents are flammable. 


   An industrial hygiene study of a university silk screen

printing class verified that silk screen printing without

adequate ventilation can be extremely hazardous.  This study

measured the breathing zone exposure of students and teaching

assistants during printing using poster inks, and cleaning using

toluene, xylene, mineral spirits, and lacquer thinners.


 Without ventilation, measured air concentrations during

printing were 100 parts per million (ppm) of toluene for 100

minutes, 600 ppm of toluene and 92 ppm of xylene for 421 minutes,

and 410 ppm of toluene for 60 minutes.  During cleaning, the

following measurements were made:  670 ppm of toluene for 28

minutes; 490 ppm of toluene and 250 ppm of methyl ethyl ketone

for 8 minutes; and 1900 ppm of toluene, 95 ppm of xylene and 180

ppm of methyl ethyl ketone for 34 minutes.  


   With local exhasut ventilation, the exposure levels were many

times lower with most measured concentrations below 1 ppm, and

all below 50 ppm.   By way of comparison, the American Conference

of Governmental Industrial Hygienists (ACGIH) has set Threshold

Limit Values (TLVs) of 100 ppm averaged over an 8-hour day for

toluene and xylene, and 200 ppm for methyl ethyl ketone.  The

ACGIH 15-minute TLVs are 150 ppm for toluene and xylene, and 300

ppm for methyl ethyl ketone.  As you can see, the air sampling

carried out greatly exceeds these ACGIH recommended exposure

levels.



Screen Preparation  

   The hazards associated with screen preparation depend on the

materials used.  For resist and blockout stencils we recommend

water-soluble glues, liquid wax and liquid frisket which contain

no toxic solvents nor require them for clean-up.  They may cause

slight eye irritation if they splash in the eyes.  Lacquers,

polyurethane varnishes, tusche, shellac and caustic resist

enamels are often used but contain large amounts of toxic

solvents.  Turpentine, used to thin tusche, may cause skin or

respiratory allergies, and kidney damage.


 For film stencils, water-soluble emulsion films are

recommended.  The mixture of water and isopropyl alcohol adheres

the stencil to the screen, and while flammable, is only slightly

toxic.  The adhering fluid for lacquer-type emulsions contains

acetates, ketones and alcohols, which are irritating to the skin

and are more toxic by inhalation.  


   The safest type of photostencils are diazo photoemulsions. 

They are eye irritants by direct contact, but are otherwise not

very toxic.   Ammonium dichromate, often used to sensitize

photoemulsions, can cause skin ulcers and allergies with direct

contact and inhalation of the powder can cause severe respirat-

ory irritation, ulceration of the nasal septum, and respiratory

allergies.  Ammonium dichromate is also combustible.  Silver

nitrate, another sensitizer, is corrosive to the skin and eyes. 

Carbon arcs, sometimes used to expose photoemulsions, are highly

hazardous, giving off metal fumes, ozone and nitrogen dioxide,

which are strong lung irritants, and ultraviolet radiation which

harms the eye; carbon arcs are not recommended.



Printing and Drying 

   Many silk screen inks contain up to 50 percent hazardous

organic solvents.  Poster inks can contain toluene and xylene,

which are highly toxic aromatic hydrocarbons, and large amounts

of mineral spirits.  Other inks, e.g. vinyl inks, can contain

large amounts of other highly toxic solvents, for example,

isophorone.   The bases, thinners, retarders, etc. used with

these inks also contain similarly hazardous solvents.

   Direct exposure to the solvent vapors from the ink is a

serious problem during printing due to the close proximity of the

printer.  Inhalation of the hazardous solvents during drying,

however, is the major source of exposure since large volumes of

solvent evaporate into the air in a short period of time.     

Curing fabric inks by heating may release fumes which are

irritating to the respiratory system.



Clean-up  

   Clean-up is probably the most hazardous step in silk screen

printing because of the widespread use of highly toxic screen

washes and the practice of tossing solvent-soaked rags in open

wastepaper cans.  This causes the evaporation of large amounts of

highly toxic vapors.  



To reduce exposure to toxic vapors during

clean-up, substitute mineral spirits (or mineral spirits with 15%

added xylene for difficult jobs) for lacquer thinner, toluene,

xylene and other highly toxic solvents.  These solvents are also

fire hazards.      





Precautions   

   Proper safety is essential when working with all these toxic

substances.  The elderly, people with chronic diseases, pregnant

women, and children are at especially high risk and should avoid

screen printing if possible.  Consult your physician if you

suffer from heart trouble or a breathing ailment which can be

aggravated by toxic vapors.  The following precautions will help

reduce the dangers in the processes of screen printing.

  

Fire Precautions

   Solvents should be stored in approved, capped flammable

storage cabinets.  Only a small amount of solvents should be out

for use and solvents should be purchased in the smallest

quantities practical in order to minimize fire hazards.  Before

starting work, all sources of ignition should be eliminated.  See

the CSA checklist on storage and use of flammable and combustible

liquids.



Ventilation

   One of the most important precautions in silk screen printing

is proper ventilation.  Research conducted by the Harvard

University School of Public Health in a university silk screen

printing classroom, showed that printing without adequate

ventilation causes exposure to very hazardous levels of the

solvents used.  All processes producing solvent vapors --

including printing, drying and screen washing -- should be done

with local exhaust ventilation.


 During the printing process, the best type of ventilation

would be an explosion-proof slot exhaust hood located at the rear

of each printing station.  The drying rack should be enclosed on

the back, sides, and top, and the solvent vapors exhausted from

the rear.  For example, an explosion-proof window exhaust fan can

ventilate the drying racks, if the enclosed rack is placed right

in front of the window.  


   Clean-up can be done at the printing table utilizing the local

exhaust slot hood.  Bleach cleaning of the photoemulsion screens

also needs local exhaust ventilation because of the chlorine gas

produced.  


   Air conditioners do not adequately ventilate screening

processes because they recirculate air rather than exhausting it. 

(Even when air conditioners are set on "exhaust" they recirculate

about 95 per cent of the air).  Likewise, open windows or doors

are not adequate ventilation for solvent-based silk screen

printing.



Respirators

   A National Institute of Occupational Safety and Health 

(NIOSH)-approved respirator with organic vapor cartridges can

help minimize exposure to screen printing solvent vapors if

ventilation is not adequate.  Sources for respirators and rules

for selection and use of respirators are included in the Center

for Safety in the Arts (CSA) data sheet on Respirators (see CSA

Publications List).



Eye Protection

   To prevent eye irritation caused by splashes, wear lightweight

plastic splash goggles while pouring or working with paint

removers.  Choose goggles which are approved by the American

National Standards Institute (stamped with a "Z87"). These can be

found in most chemistry supply houses and safety equipment stores

and some hardware stores.  If ink or other hazardous material is

splashed in the eyes, flood the eyes with water for at least 15

minutes and call a physician.  A source of clean water (e.g.

eyewash fountain) should be accessible for this purpose.



Hand Protection

   Gloves should be worn during all screen printing processes to

protect the skin from hazardous pigments, solvents and other

chemicals.  Ordinary rubber dishwashing gloves or surgical gloves

will not provide adequate protection.  All gloves do not provide

protection against the same materials.   When using inks, gloves

that protect against aromatic solvents and petroleum distillates

should be used.  Lacquer use requires wearing gloves that protect

against ketones and alcohols besides aromatics and petroleum

distillates. 


You should find out the type of solvents in the

products you use by consulting the specific MSDSs.  (For further

information on gloves, consult the CSA "Glove Selection" data

sheet).  To further decrease the risk of skin contact wear long

pants, a long sleeved shirt and an apron.



Disposal

   Solvent-soaked rags should be stored in approved oily waste

cans which are emptied daily.  Disposal should be done in

accordance with local city and fire regulations, and an approved

waste-disposal firm may be necessary for large quantities of

solvent waste.  Never pour solvents down the drain.  Small

quantities of solvents can be evaporated under a fume hood or

outdoors.  



WATER-BASED SCREEN PRINTING



   Because of the extremely high cost of providing adequate local

exhaust ventilation systems in classroom situations, there has

been a switch to water-based screen printing products.  In recent

years the quality of these inks has improved remarkably, and many

professional artists as well as printing studios have switched to

water-based products.  Flat, opaque, hard-edged traditional

looking prints are still possible, and dye-like transparencies

and washes rivaling watercolor and lithography can also be

produced.  The same wide variety of stencils can be used with

this medium as with the solvent-based inks.  


   The changing over to water-based inks means the incorporation

of a whole new system and requires understanding of this new

medium.  It is necessary to take time and learn how to produce

successful images.   


After learning how to work with water-based

products, artists and instructors report that the colors are

beautiful, the inks don't dry on the screen, and paper designed

specifically for water-based screen stays flat.  In addition the

overall cost of printing with water-based silk screen inks is

cheaper than with solvent-based inks because water is used for

cleanup rather than the more expensive solvents.



Hazards

   The inks and cleaning materials employed in water-based screen

printing use water instead of toxic organic solvents. Airborne

organic vapors, skin absorption of organic solvents and the risk

of fire are greatly reduced.  Small amounts of organic solvents

may be used in water-based screen printing inks.  



We recommend products with only water, propylene glycol or ethylene glycol. 

Glycol ethers such as cellosolve are much more hazardous since

they can cause anemia, kidney damage, and adverse reproductive

effects such as miscarriages, birth defects, testicular atrophy

and sterility.  It is necessary to get material safety data

sheets (MSDSs) on all products in order to ascertain the ink

composition, since the ingredients are not always listed on the

label.    


   Use of diazo photoemulsions can completely eliminate the need

for solvents.  If lacquer stencils are used, then the hazards

discussed earlier for solvents will apply, although to a lesser

extent since smaller amounts of solvents are used.



Precautions

   Basic personal hygiene is a must for all those working with

art materials.  Water-based screen printing is no exception. 

There should be no eating, drinking, smoking or make-up

application in the studio or while working.  



Hazardous pigments and some  toxic solvents are still used in the manufacture of

water-based inks and related materials.  To avoid ingestion and 

absorption of these substances through skin contact, wearing

gloves is recommended while working in this medium. For water-

based printing, a window exhaust fan should provide adequate

ventilation and costs much less than a slot exhaust hoods or

other complicated ventilation systems.  If lacquer stencils are

used, then one explosion-proof slot exhaust hood would be needed

for this process.



REFERENCES



Babin, A. and Rossol, M: "Glove Selection". Center for

  Safety in the Arts, New York (1988).

Clark N, Cutter T, and McGrane J: Ventilation.  Nick Lyons

  Books New York (1984).

Johnson LM and Stinnett H: Water-based Inks: A Screenprinting

  Manual for Studio and Classroom. Philadelphia Colleges of the

  Arts Printmaking Workshop (1987).

McCann M: Artist Beware: The Hazards and Precautions in

  Working with Art and Craft Materials. Watson-Guptill, New York

  (1979).

McCann M: "Silk Screen Printing Hazards." Art Hazards News

  2:7 (1979).

McCann, M:  "Respirators". Center for Safety in the Arts, 1988.



SOURCES OF ADDITIONAL HELP



   Written and telephoned inquiries about health hazards in the

arts will be answered by the Art Hazards Information Center of

the Center for Safety in the Arts (formerly the Center for

Occupational Hazards).  Permission to reprint this data sheet may

be requested in writing from the Center. For a copy of our

publications list, send a self-addressed, stamped envelope to:

Center for Safety in the Arts, 5 Beekman Street, New York, NY

10038. Telephone 212/227-6220.

   This data sheet was revised with the assistance of a grant

from Special Projects, Visual Arts Program of the National

Endowment for the Arts.  The Center for Safety in the Arts is

partially supported with public funds from the National Endowment

for the Arts, the New York State Council on the Arts, and the New

York City Department of Cultural Affairs.



(c)  Copyright Center for Safety in the Arts 1988