Thursday, October 23, 2014

How to Print with Thermofax Screens Tutorial

A thermofax screen is made from a black and white image along with a piece of mesh that has a plastic coating on the back; the two are run through a thermofax machine to burn the image into the plastic side of the screen.  The edges of the screen are then taped with waterproof duct tape to add weight and keep them flat, and to make a “well” for placement of paint.  The screen works like a stencil, but much more detailed images are possible.  Screens can be used over and over again.

Tools needed for printing include a padded printing surface – a piece of craft felt covered by a double layer of muslin or canvas works fine.  I recycle Styrofoam meat trays to use as a paint palette & hold supplies.  Small plastic baby food spoons are great for fitting inside paint jars.  You’ll need assorted sizes of squeegees (you can find a set of 3 graduated sizes in the detailing section of an auto supply store - AutoCraft and Bondo are 2 brands), including expired credit cards.  You may want to use foam brushes for more precise color placement.  And of course, textile paint – some brands include Jacquard, Speedball, Simply Screen, ProFab, Versatex, Stewart Gill, Tulip.  Finally, a cat litter pan is perfect for washing your screens, and a toothbrush helps clean off all the paint.

Start by putting a bead of paint across the screen; in this instance I will pull the paint from top to bottom, but you could also go side to side.

Here I am using a credit card to pull the paint across the image on the screen.  When it’s the first pull, you may not get a clean print – the first pull kind of “primes” the screen; you’ll probably need a second pull to get a better print.  After there is more paint on the screen, you should be able to get a clear print with one pull.  What you can’t see in this picture is that my other hand would be holding the top edge of the tape securely to keep the screen from moving (in this instance it was taking the picture!).  There is another picture later that shows this clearly.  Here’s the first print.

There are ways to work in additional colors.  I started with red, and then added some orange.

You can see on the right how the colors blend as you pull the new color across the screen.

Another use for the meat tray holding supplies is that the raised edge makes a good place to rest the squeegee when you need to set it down.  Here I’ve added a 3rd color, burnt orange, which is a metallic paint with a bit of sparkle.

Here’s a better view of using my left hand to hold the screen in place while I use my right hand to squeegee the paint across the screen.  You need to be careful to keep the screen stationary to get a clean print.  You might also like to use blue painter’s tape to hold the screen in place, especially if placement is very important.  Below is a better view of pulling the credit card/squeegee.  Try to keep it at a 90 degree angle to the printing surface.

Here I’ve added some yellow to the other colors already on the screen.  You can see the print on the right.  As you continue to print the colors blend on the screen and squeegee.  Be careful about combining colors that are opposites on the color wheel – you might end up with mud brown.

In the next group of photos you’ll see that I continued printing until I’d used up as much paint on the screen and squeegee as possible and still get a clean print.  At this point you could just wash the screen, but there’s still a good bit of paint there.  If you take a small sponge, wet it, and squeeze out most of the water, you can wipe that across the screen and continue to print with the water in the sponge diluting the paint enough to print.  Pull the paint from the outside edges in towards the center of the image.  This can be done on small pieces of fabric, scraps, paper, whatever you like – rather than washing that excess paint down the drain, you can get a surprising number of prints from it.  When you can no longer get a clear print, drop the screen and other tools in the pan of water.

I couldn’t fit it all in this picture, but I got 8 more prints from the screen using the sponge to clean off the excess paint.

Above are the “regular” prints I did before the clean-up prints.  It’s hard to tell the difference.  Finally, everything gets tossed into the pan of room temperature water for clean-up.  Use the toothbrush to gently clean the screen on both sides, as well as the squeegees, spoons and anything else used.  Pat the screen dry with a terry towel and allow it to completely air dry before storing.  Wet screens stacked together may stick and then the plastic may pull off when you try to separate them.  With proper use and care, thermofax screens should give you hundreds of uses.

No comments:

Post a Comment