Screen printing is the process of printing designs on fabric using a screen. It is a popular method of producing many types of clothing, posters, shopping bags, and of course T-Shirts. Screen printing is one method that will be used to provide printed t-shirts that generate nearly $600 million dollars in the United States, alone.
What Supplies are Needed for Screen Printing a Shirt?
The following are items used in the screen printing process. Just looking at this list of items makes it look to be a daunting task, but most are not that hard to find and are relatively inexpensive.
One of the most important elements of screen printing is obviously the screens, one screen for each color. A printing screen is made up of a frame that has a cloth mesh stretched over the top of it. The screens are then coated with an emulsion (discussed later) so that they can receive an image to be put on something.
Transparency sheets allow images to be put on the screen. One transparency of each color is required. This is like the negative of the image so that the ink is blocked from the blank parts. Where the image gets ink the image will be black, where it doesn’t get ink it will be clear. This way the emulsion gets exposed to light, and it turns hard, the parts that are blocked off from exposure will be washed away. Easy peasy.
Screen printing emulsion to coat each of the screens. Each screen gets a thin layer of emulsion which will allow it to change for the image to be printed. Treat your screens nicely, they will be used not only for hundreds if not thousands of transfers but they will be able to be used for dozens of designs before needing to be replaced.
Tape measure to ensure proper placement of the shirt and screens. As you gain experience you will develop your own shortcuts for shirts and placement on the platen. Initially, though I would definitely recommend that a measuring tool be used.
A fabric glue of some type is used to hold the item in place when it is being printed. We do have a video on the glue types that can be used. We do recommend that liquid glue is used for multiple reasons, other than the spray adhesive. (https://www.youtube.com/watch?v=EQSVB5YNPVc)
One thing that is left off of the list, and that I frequently forget is a masking tape of some kind. This blocks off the edges of the screens so that the ink doesn’t seep through the spots that don’t have emulsion on it but still should not get printed. I would suggest having the blue painter’s tape in a one-inch roll and also in a two-inch roll. This gives some flexibility so that an image can be blocked correctly.
Inks for each of the screens. These inks come in many types such as discharge inks, plastisol ink, water-based inks are the most commonly used type of inks. We will fully discuss these inks in a later post.
Squeegee to pull the inks across the screens. A different squeegee is used for each of the screens. It’s best to keep the squeegees in good condition as they are one of the more critical components of the process.
Heat gun or a flash dryer unit to heat the transferred inks so that they properly cure. For example, plastisol inks cure best at a temperature of 320°F (160°C), water-based inks from 300°F-320°F (149°C-160°C), and discharge ink at 320°F (160°C). Proper curing prevents your screen prints from cracking as they age.
As long as you are heating the inks to a certain temperature range you might as well have an infrared thermometer. This allows you to check to ensure that proper curing is going on with the inks. While the temperatures do not have to be exact it’s better to at least know what they are.
Where to Buy Screen Printing Supplies?
Screen printing supplies can be found at most local print shops, craft shops, and several online retailers. Some common supplies include inks, frames, and adhesives.
Michael’s Stores are found throughout the US and allow you to see what it is that you will be buying. They offer a full-on kit for starting this screen printing adventure, it’s how I and many others got started learning to print.
Hobby Lobby stores are an excellent source when getting started with screen printing. They offer some small screens, emulsions, and smaller-sized containers of inks.
How to Use These Screen Printing Supplies?
Once the screen or screens have been coated with a photosensitive emulsion they need to dry, someplace where ‘the sun don’t shine” (or anyplace dark). This will prevent the screen from being prematurely exposed.
These photosensitive screens will then need to be exposed using the transparency that has been prepared. This can be done using either a commercial exposure table, a stable light source, or even in the sunlight on a bright day. This is one of the more critical steps of preparing for screen printing. The exposure of the screen can make or break the quality of the final print. There will be one screen prepared for each color in the final product. Don’t forget to add registration marks so that you can align the colors perfectly.
After the screens have been exposed they will need to be washed so that the unexposed emulsion is rinsed off of the screen. Depending upon the emulsion that has been used, this process sometimes requires quite a bit of pressure. Make sure that there are no holes in the screens and the emulsion that was not rinsed away looks right. This will all become second nature and unfortunately, I can’t describe what it looks like, but you will know “wrong” when you see it.
This open part allows the ink to flow to the shirts that are being printed. Once they are washed they will of course need to be dried. This can be done with a hairdryer, a fan, or, if you are feeling froggy, just grab a leaf blower and use that. (OK, I have never felt froggy so I have never used a leaf blower, so I am not sure that would work. But I guess it could work. Just be sure and make sure that the screens don’t go flying out into the ligh.)
Next, mount the screens on the screen printer and align them on the platen. Make sure that you are using the registration marks for proper alignment.
Place some ink of the proper color on the screens once the alignment is set. Generally, a bead of ink is laid on the side of the screen opposite of the operator. The amount or thickness of the bead will vary depending upon the printed object. If it’s a wide and high tree, for example, it may need a lot of ink, therefore, it will need to be thicker than a single line being printed.
With the first pull of the squeegee, it is generally best to use the heat gun or flash dryer and cure that first layer. This helps to keep it from bleeding into the other colors as they are printed.
Once that first layer is cured, rotate the screens to add the next color onto the object. These next colors do not need to be cured individually they can all be cured at the end.
Additional Equipment to Consider Eventually
As your screen printing picks up you can add more equipment.
One item that can make life easier for a screen printer is a flash dryer, and then eventually a conveyor dryer. Each has its advantages, the flash dryer is portable and can be moved to the item being printed for that initial curing. After the first pass of the ink, simply move the flash dryer over the platen of the printer and cure the ink for a certain time.
The conveyor dryer is built to use as the final step in the curing process. Place a printed piece on one end of the conveyor and the machine pulls it through at the preset speed so that the ink is cured in one simple process. The advantage is that multiple items can be added to the conveyor so that the curing can be much more automated.
An exposure table is something that the larger shops have to make consistent and uniform screens. These tables provide consistent exposures with a bank of evenly spaced lights designed to expose the emulsions of screens.
While it isn’t required it definitely makes life easier if you have a dark room with a power sprayer, a water supply, exposure table, and an unlimited supply of iced tea, no sugar, please. I can’t forget, there must be a refrigerator to keep my hobbies in, including film stock for all of the various cameras that I have. Plus all of the money to buy said film. What the hey, right? A man can dream!
In case you haven’t noticed there are a lot of ways to go with screen printing. You can go all out and buy a 12 color 16 workstation printing press or you can start with a single screen and a squeegee and some ink. It’s best to learn the process and then figure out where you can take it. Printing on t-shirts, leggings, hoodies, hats, and underwear is the same basic concept, and it’s critical to practice before jumping into the deep end and spending a fortune on equipment and supplies.
Basics to get:
- Design
- Transfer
- Emulsion
- Screen
- Ink
- Squeegee
- Dryer of some kind
That’s it! Now go start making screens and printing something!