Sunday, November 9, 2008

Silkscreening is the jam-pony!


I taught a silkscreening class at the AS220 Community Printshop the other day and it was pretty awesome to help people realize the potentials of this medium. You can read a ton of books or articles on the Internet on how to do it but sometimes all the information can be overwhelming. It tends to make you feel like you have to start out with a bunch of expensive materials and a lot of technical finesse. I wanted everyone to leave knowing that you can start out pretty cheaply and that you probably already have half of what you need to make a decent print. Here's the list of what I passed out to them as a quick primer on all the alternatives that I've gleaned from books and friends over the years. I've done almost all of these, minus making inks from wallpaper paste but I don't doubt that it works!
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Handmade photographic stencils:
You can use a variety of materials to make your own artwork on transparent film, translucent vellum or acetate. Dura-Lar is a good acetate alternative and you can buy it from art stores in books of 25 sheets or so, or in rolls, which is cheaper.
Drawback in buying it in rolls: you can’t run it through copy machines.
Advantage: you can make stencils that are larger than the normal printing sizes offered on most commercial copiers, which is usually 11x17 inches.
-Draw or paint directly on the film, vellum or acetate with an opaque medium, such as a permanent marker (any oil or water-based opaque paint marker- sold in art stores), India ink, china marker, tushe stick or tushe liquid. (Tushe is a waxy, greasy product used primarily in lithography).
Note: Dura-Lar is also useful to have around for registering your prints.

Using photographs:

Unless you are able to tweak your images into a half-tone pattern using software such as Photoshop, the key to success is making sure that the image you create is one of high black-and-white contrast, without the continuous range of gray-tones in between. You can mess with the contrast of your image on copy machines or in Photoshop to create images that will print easily. The advantage to this technique is that you can have a photo realistic image and can also draw in other objects or text to introduce your style, or “hand,” in the piece that you are working on to make it more personal. Print out your image, add some drawings and then copy the completed image on acetate at the copy shop.
In some cases, you need to double up your completed acetate if the toner doesn’t print out opaque enough- simply line them up and tape together using a clear tape. If you are burning screens at home in a more makeshift fashion, I recommend always doubling up your acetates to guarantee a successful exposure.

Paper stencils:

Surprisingly simple, this method can nevertheless yield quite sophisticated results without the need of burning any screens at all. Paper stencils allow you to print sold shapes of color (and relatively simple designs), one color per stencil. Working with your master drawing, trace the areas that you want to print and cut out using an exacto-blade. You can use any type of paper, but I’ve found wax paper works best since it doesn’t absorb any of the ink. The trick with wax paper is to use rubber cement to adhere it to the underside of the screen so that it won’t “float” while you are printing- this allows you to have more consistent registration. If you end up using regular paper, the ink will hold the stencil in place after the first squeegee swipe but you should loosely tape the edges to secure it to the back-side of the screen before you begin printing.
While I have read that you can use this technique for a run up to 500, I have found that it works best for 30 or less prints and where color registration isn’t such an issue.

Direct Stencil Techniques:
Direct stencils are created by applying a block-out medium directly to the screen in the areas that you don’t want to print. These products, such as commercial screen filler and masking tape, serve as the stencil because they block the ink from penetrating the screen.
The basic idea is that you trace out your design onto the screen and then paint in the screen filler (filling in what you don’t want printed), trying to make sure that you don’t leave any pinholes.
Instead of trying to block out the screen using screen filler, you can use drawing fluid in combination with screen filler to make a stencil. To break it down simply, you paint out your image using the drawing fluid, allow it to dry and then you pull screen filler over the image using a squeegee or piece of cardboard. (The drawing fluid resists the screen filler much like wax resists ink.) Follow the manufacturers directions on how to wash out the drawing fluid and the resulting open areas, where the drawing used to be, will now be ready for printing.
These techniques can be way more spontaneous and is a good way to do reductive printing, however the drawback is that it can be more time consuming and that it’s also harder to reclaim your screen unless you have access to a power-washer.


Inks:

With inks, it all comes down to what you plan to print on. Water-soluble inks remain water-soluble when dry, whereas acrylic inks will be water-proof. You can buys inks already pre-mixed or can mix your own. Adding transparent base extender will not only help make your colors more transparent but will make your inks last longer. I’ve used house paint (with base extender added to make it more the same consistency of silkscreen ink) for years and find it to be cheaper, easily found and it works great for printing on paper. The only problem is that it isn’t archival so I can’t attest that it will stand the test of time.
A weird thing that I read but haven’t tried is to use wallpaper paste as an ink base. You mix up a small quantity of wallpaper paste to the recommended paste/water proportions and add powder paint or fabric dyes. To tone down colors, add the opposite color on the spectrum- if you are good at mixing colors, this might be something worth trying because in the end, you may save a fortune on inks and can create any subtlety desired.
For fabrics, you really need to use textile ink, otherwise it will wash out! You also need to heat set the ink before it’s put in the wash or is exposed to water. This can easily be done by either using an iron (make sure to put a piece of fabric or paper in between the iron and the printed image, otherwise you can melt and smear it!), or by putting the final product in the dryer for 10 minutes or so. If you aren’t ever going to wash the fabric, acrylic ink will work fine.

BARE-BONES HOME EXPOSURE UNIT:

(Taken mainly from Simple Screenprinting- Basic Techniques and Creative Projects by Annie Stromquist with extra notes to simplify.)

-1 or 2 bath towels
-Black cloth
-Piece of clear glass just smaller than the inside dimensions of the screen
-Aluminum lampshade, 10 or 12 inch, or disposable aluminum foil pan
-Standard light socket
-250 watt household bulb
-Extension stand or arm from which to extend the light to the proper height and position in the center of the exposure area
-Tabletop on which to assemble the parts
-Timer

Note: In lieu of the lampshade and light socket listed above, you can also use a commercial work light with an aluminum shade, available from any home improvement center. Be sure it will accommodate a bulb in the appropriate wattage specified- you don’t want to start a fire. High wattage bulbs can get super hot and melt the socket!

It is really easy and inexpensive to set up your own exposure unit and the hardest part is to find an out-of-the-way, darkened spot for the procedure. A space in the closet, basement, bathroom or any other room that can be kept in the dark for the duration of the process will work. You can set up your table as needed and disassemble after you use it if you can’t set up a permanent location.
Your workspace doesn’t have to be in complete darkness and you can use ambient or a safelight to get to work. I’ve read of people using night-lights with a red Christmas tree bulb as a safelight!
-Fold the bath towel in half and lay it on your tabletop to serve as a cushion; if one folded towel is smaller than your screen, use two unfolded bath towels.
-Spread the black cloth over the towel. The black cloth will absorb light, preventing it from bouncing back up and interfering with the exposure of your screen.
-Lay the prepared screen, well side up, on top of the black cloth. Center the vellum or transparency with the prepared imagery on top of the screen, facing up. Place the glass on top, first making sure that it’s clean and free of streaks and scratches. The glass insures that the prepared imagery will make the proper contact with the screen.
-Measure the approximate outside dimensions of the image- this will determine how far away the light source should be. Refer to the chart provided by the manufacturer of the emulsion product for this information.
Note: You may have to make a test screen in order to figure this out if you don’t have access to that information. The main thing is that you want the light to evenly cover the whole image that you want burned. Some investigating on the internet will probably yield some good advice to follow- message boards are particularly useful in trouble-shooting and asking questions if you need extra help.
-When all the elements are in place, turn on the exposure unit and set a timer.
-Turn off the light at the end of the designated exposure time which could be anywhere from 10 to 90 minutes.
After the screen has been exposed, take it to your cleaning area and begin to rinse- wet both sides with a gentle spray and concentrate on the image areas. The image will wash away, leaving open mesh in these areas. You can assess your progress by holding the screen up to the light- once you are done, dry your screen and when it’s dry, you’re ready to print!

BURNING SCREENS IN THE SUN? FOR REAL!
You can burn screens using the sun but due to all the variables, you will never have a consistent time. Read more on the internet of how people have done it in your region. For example, in Florida, I knew of people with exposure times of less than a minute in full sun. You can prepare everything on a board (as you would for an indoor set-up), cover with layers of dark cloth or black garbage bags, run out to expose, cover and then rinse.

FINAL WORD:

This is only a super simplified list of materials and techniques that you can use to silkscreen; the possibilities are endless and there are many combinations of techniques and processes to achieve a myriad of results. Don’t be afraid to experiment, to ask others how they work and what kinds of materials they use. Some things that I’ve listed are the most primitive way to do it but if it works, it works! In general, that’s a good motto to have when you don’t have access to better equipment or a good set-up- but you want to still be able to make your art.