How to Screen Print T-shirts at Home or Small Business
Preparing an Image For T-shirt Screen Printing
A T-shirt is a blank canvas ready for whatever you can conceive- the options are limitless! Not all shirts need to be funny or clever. Some of the best shirts just have a unique or great looking image. What you do need to keep in mind as you create an image, however, are the technical limitations and requirements involved in getting it to look good on a T-shirt. These might include intricacy of the image, number of colors and placement on the shirt.
Starting Your Image
For at least your first design, it would be wise to start with only one color so you get comfortable with the basics of printing before tackling registration. Additionally, t's much easier to print dark ink onto a light shirt, so starting with black ink is also a good idea (more on this later). But regardless of the color you will be using to print onto the shirt, you need your initial image to be black and white in order to get it onto a screen for printing. If you sketch it out in pencil, you will then need to trace it in black ink. Rather than putting the ink directly onto your pencil drawing, use a second piece of paper and trace it on a window (so you can see the image through your top paper) or, better yet, use a light box.
Below is an example of a pencil drawing (left) that is not yet suitable for printing because there are gray areas that are neither 100% black or 100% white. The frog was then traced using black ink onto a clean piece of paper, producing the correct type of image at right:
Once you've got a dark image like the one above on the right, scan it in and tweak it using Photoshop or other image manipulation software. This might include erasing any errant lines or marks. Likely you will need to adjust the "levels" (in Photoshop) to turn any light gray areas white and the dark gray black.
If you have a graphic tablet, you can skip tracing it with pen by scanning in the pencil drawing and "tracing" it in the computer.
Position Your Image on the Shirt
Before you "burn" your image onto a screen for printing, you'll want to be sure it's going to look good on a shirt. Print out a test image or multiples at different sizes onto scratch paper. Cut off the excess paper around the image and tape your design onto a shirt you or an assistant is wearing. Move it around until you like the position. Is the size right? If not, adjust the size and print out a new test image. Continue this process until you are happy with how it looks and is positioned on a shirt.
From Drawing to Silkscreen
Now you need to get your design onto a screen for printing. To do this, you need to first print it onto a transparent surface of some sort (options explained below). This is because in the process of "burning" an image onto a screen, you want light to travel through parts of the image you DON'T want printed, and you want light blocked by the parts of the image you DO want printed. (This will be explained in the burning a screen section, don't stress it if it doesn't make sense yet.) For this reason, the darker your image, the better; the more transparent the background, the better.
Transparencies for Screen Burning
The best option is to print your image onto a transparency. The problem is that a normal transparency will not accept ink from a regular inkjet printer. You'll need to buy "inkjet transparency film". It's expensive, but it's worth the price given the headache it will save when you burn your screen. (A good source is here: inkjet transparency film.) Most images that end up on shirts need to be larger than a standard 8.5" x 11", so you'll need to buy a larger size, such as 11" x 17" or 13" x 19" and have access to a large-format inkjet printer. (Otherwise you'll need to piece together multiple transparencies, which is doable but not ideal, especially if there are no breaks in your image.)
You'll need to experiment with your printer settings to get the blackest, most solid print you can. The darker it is, the easier it will be to burn your screen. If you get really solid black lines, you'll be less likely to overexpose your screens.
Another option is to have your images printed by a local copy center. It's not very expensive, but I've never found one that has transparencies larger than 8.5" x 11" (and I called dozens in my search). TIP: If you don't have access to your own large-format printer, you may be able to buy the larger inkjet transparency film and bring it to a copy shop to have them print it.
[There are other options, but I don't recommend them. One is to use vellum, which is a translucent paper that will accept ink from your inkjet printer. Another is to use regular printer paper and soak it in some sort of cooking oil (AFTER printing on it already) to make it translucent. You'll save money, especially using the oiled paper method, but because less light will travel through the paper, you'll have to burn the screen longer, risking overexposure.]
This is skipping ahead, but see how the frog image shown above will look when printed (this time on a screen printed necktie):
Now that you have an image suitable for printing and have it printed on a transparency, it's time to burn it onto a screen. But first, make sure you have selected the right screen for your image! Learn about how on the next page.