Do you want to know about Screen Printing? Check out this easy to follow screen printing how to guide
- Prepare your artwork.
- Print film positives.
- Expose your screens.
- Set up your press.
- Print your shirts.
- Clean up.
- Watch as Monument tells you how to silk screen .
Prepare your artwork –
To print a shirt you need a graphic to print onto the shirt. You can create it, copy it, or a customer can bring it to you. When creating your art keep this in mind, garbage in = garbage out, the better quality art you start out with the better screen prints you are going to get.
Print out your film positives –
When you screen print a shirt you print one color at a time. If you’re artwork has multiple colors, you need a way to separate those colors, and burn a screen for each color. Most screen printers use Corel Draw, Adobe Illustrator, or Photoshop as their artwork creation program. Then use a Raster Image Processor or RIP in order to separate and print the film’s for screen printing.
Once your artwork is created and separated using a RIP, the next step is creating a film positive to burn your image into a photo sensitive screen.
A film positive is a solid black image printed on a transparent sheet. The solid black image serves as a UV light blocker, and the transparent sheet let’s UV light hit the screen hardening the unblocked emulsion and leaving the blocked emulsion water soluble ( You can rinse it out with water – see image below), Most printers use a large format modified inkjet printer to print thick opaque black ink on the clear film.
Expose your image into a screen –
You have the art, you printed your films, now its time to make the screen.
A screen printing frame consists of a wood or aluminum frame stretched with polyester mesh on it. The mesh get’s coated with light sensitive emulsion, the screen is exposed with UV light, and rinsed with water to create a stencil on the screen. When you pull the ink across the screen with a squeegee, the stencil lets ink pass through the opening and onto the t-shirt.
The emulsion on the mesh hardens with UV light. The black image printed on the film transparency blocks the light from reaching the emulsion, this leaves that area of the emulsion unexposed and water soluble. This is why its so important to ensure you have a very black film, if your film is only partially black, it will let light in during the exposure process. After the screen is exposed, simply rinse it with water, the soft part that was not exposed with UV light rinses out leaving that area of the mesh open so you can print ink through it! The exposure process is complete and your almost ready to start screen printing shirts!
Set up your screen printing press –
Alight, its almost go time, but before you start printing you need to setup the screens on your screen printing press. A screen printing press consists of a base that holds you printing platen and a number of color arms (depending on how many colors your press is.) A manual press can be as small as a 1 color 1 station, or as large an 10 color 8 station. If you have more color arms you have the ability to print more colors on the shirt likewise if you have a higher a mount of printing stations, you can print faster. Right before you clamp your screens into your press you tape off the edges of your frame with screen tape which helps keep the screen and shirt clean during printing. If you are printing a multiple color job, you’ll need to register the colors together so that they line up when you print all of them at once on the shirt.Using a press with micro registration is a must when printing fine detail multiple color jobs. Once your screens are in registration, do a test on an old shirt or a printing test pellon to ensure everything lines up.
It’s time to print! –
Screen printing a shirt actually goes pretty fast when you get all setup. There are a few things to keep in mind during the printing process. First is called flashing, if you are printing on dark garments where you have to use a white under base under color ink or if you have ink touching other ink, you’ll need to flash dryer in order to cure/set the ink giving you the ability to print another color on top of your first layer.Flashing only takes about 10-15 seconds, but it does slow the process down, typically shirts that need flashes are sold for more due to the increased production time. Once the shirt is printed it needs to cure in order for the ink to stay set into the garment. Ink cures at 320 degrees through the entire ink film. To cure a shirt you can use an oven or heat gun (for the hobbyists), a flash dryer, or optimally a conveyor dryer. Its important to ensure your ink is cured because if it is not cured thoroughly, it will wash out of the shirt. To help ensure your ink is cured you can use a laser temp gun to measure the temperature of the ink while it is being cured.
The shirts are printed and its time to clean up –
Many people think screen printing is a messy process, it’s only super messy if you make it and don’t clean up after yourself. Cleanup is pretty easy to do. First save as much ink as possible by using an ink cleanup card to scrape it out of the screen and back into your ink container.Depending on the type of ink you use to print with you should use a screen printing screen wash to clean the ink out of your screen and to wipe down your press. If you are going to print more shirts in the future with the same design you can choose to save your screen for future use. You can also use your screen again for a different design by using emulsion remover and a power sprayer to take the image off the screen so you can start the process over again!