i really don’t like the plastic feel of many printed shirts. not only does that plastic make you sweat with large designs, it also cracks and peels if it happens to be a favorite shirt that is washed often. that is why i usually look for shirts with softer ink and usually shy away from tees with alot of think plastic ink. i was already doing batik and tie dye when i started to experiment with screen printing. since i already had the fiber reactive dye i decided to try screen printing with thickened dye. for this, i had to learn the cold batch method.
basically, with the cold batch method, you thicken the dye so that it will stay where you put it. you can use this thickened dye as paint, with stamps or with screen printing. in my case, i wanted to screen print. i love the crisp details and ease of producing artwork that comes with screen printing, so i started to experiment. if you are new to screen printing, see this tutorial to get you started.
the trick to the cold batch method is getting the dye to “set”. for that (on cotton anyway) you need soda ash and either time or heat. first we will deal with soda ash. one method is to mix the soda ash right into the dye and the thickener (sodium alginate), but when you do this, your mixture has a short pot life of about 6 to 8 hours before it becomes exhausted. the other way is to soak the shirt in soda ash and let it dry. this is nasty too because once the shirt is dry with soda ash, the soda ash can get into the air and is really irritating for the lungs so both these techniques have their trade offs. i have mostly been soaking the shirts in soda ash, but recently i started saving my printing for one day and then mixing very small amounts of colors but this process does take some time. next time i am going to try pre-mixing a concentrated dye solution and pre-mixing soda ash with very thick alginate, then mixing the two together when it comes time to dye. this process should take alot less time than mixing powdered dye and powdered soda ash because the dye and soda ash will already be in solution. it should just require a couple vigorous shakes. when i print next, i will grab some photos and update on how the pre-mixed dye solution did.
the next element of “setting” the dye is heat or time. according to the cold batch tutorial above, you should leave the garment for 12 to 24 hours in a spot that will keep the dye from drying. you could seal it in a big tub or a plastic bag. for those of us that are impatient, you can also steam it. steaming involves wrapping the shirt in newsprint and exposing it to steam and pressure for about 20 minutes to an hour. i have used this process on many many shirts with great success. this also works great for silk. recently, however, i discovered that heat from a flash cure unit will also “set” the dye and only takes about a minute. the flash cure unit also works great to dry the dye in between colors.
for the actual printing, i usually put my dye in plastic condiment squeeze bottles or in tie-dye squeeze bottles. this way, i can squeeze out the exact amount i need for each color (i will update with pics next time i am printing). find a flat surface to put your garment on and put some plastic or wood in between the layers so that the pattern doesn’t soak through to the other side. you want your screen to be about 1/8″ off the shirt with the screen side down. you can tape a quarter to the four corners of the frame to achieve this (i use a press and with that there are off-contact settings and a platen that you put the shirt on). if you don’t have a press and you are trying to do more than one color you will need some way to line up the colors. i always did this by making a thick black line next to my designs (make sure the line is in the same place for each color in the design) before burning the screen, then using chalk to mark were the line would be on the shirt. put some clear shipping tape over the line and then line it up with the chalk. this is really tricky, however so don’t expect perfect registration. make sure, also to tape off any areas you don’t want to print like the edges of your screen and any other designs (if you put more than one design on a screen). when you’ve got your screen all lined up and in place, put a thin or thick line depending on the amount of open area the design has (which dictates the amount of ink that will be used). once the line is there, use a squeegee to gently draw the dye across your pattern. this is called “flooding” and isn’t actually putting any dye on your shirt yet. when the pattern looks completely full of dye, you can forcefully scrap across it with the squeegee to press the dye down onto the fabric. since you have 1/8″ of off-contact, the screen should pull itself back up off the fabric leaving a perfect image behind.
thickened dye can dry on your screens so it is a good idea to clean the excess dye off the screen immediately after printing otherwise it could clog your screen. if you don’t get it right away, gently rinsing with some cold water should do the trick. don’t scrub or you risk damaging your stencil.
like i said, i will snap some pics next time i print to add to this tutorial. thanks for reading.
printing chemical “water” (mix 3 to 1 with concentrated dye):