How to Build a DIY Exposure Unit

Posted by Jeffrey Gononsky on

Pop artist Andy Warhol is famous for using screen printing, but he didn't invent the technique. This honor went to someone in East China during the Song Dynasty (960-1279 AD). From there, the technique became the popular printing method known today. 

Screen printing today is a lot more complex than it was a thousand years ago. But that doesn't mean you have to visit a screen printing shop to get a halfway decent screen printing project done. It is possible to make some silk screen supplies as a DIY project. 

If you're okay with having a lesser-quality print, read on. This article will teach you how to make a DIY print exposure unit. 

Making Screens With Photo Emulsion

If you're a screen printing expert, you probably know how to make screens with a photo emulsion coating. This section is more for screen printing beginners. Or you can also use it as a refresher. 

What Is Photo Emulsion? 

Photo emulsion is a coating made of a light-sensitive chemical. It allows a screen maker to create a design on top of his or her silkscreen. A screen printer will then use the screen to print designs on bags, t-shirts, etc. 

There are a wide variety of photo emulsion coatings available. Some have water resistance and others have solvent resistance. The photo emulsion you choose should depend on which printing ink you're going to choose. 

It is possible to make photo emulsion coatings. However, the coating that you create at home likely won't measure up to the professional version. You'll get a much better quality print if you buy your photo emulsion coating from a screen printing supply store. 

How to Create a Printing Screen 

To make a printing screen, a screen printer will first coat their silk screen with photo emulsion. They will then tape a design image to the screen. The design image should be transparent except for the design letters, pictures, etc. 

The screen will then put everything into the print exposure unit. Inside the exposure unit, the photo emulsion will disappear underneath the design letters. 

Once the screen printer takes the silk screen out, it should be ready for printing. 

What Is a Printing Exposure Unit? 

A printing exposure unit is a large piece of printing equipment. One can almost describe it as a cross between a tanning bed and a scanner. It's a box with UV lights into which one can put a photo emulsion-coated silk screen. 

The exact control that one has over the UV light differs between exposure units. Some have timers. Others let you change the power level of the lights. 

Exposure units can be effective tools, but they can be expensive. Luckily, if you don't have the monetary resources, you can make a lower-quality exposure unit. This is also a good idea if you want to do screen printing as a hobby or in some other casual manner.

Exposure Unit DIY Project Directions

This set of directions will cover exposure units with UV lights. It is possible to make exposure units that use real sunlight. But you'll need to use another guide to learn how to make a unit of that style. 


For this type of DIY exposure unit, you'll be making something akin to a table with a glass top. If you can find a glass-top table that meets your needs and wants for length, width, and height, you're already done. But if you can't or don't want to look for such a table, gather these tools: 

  • 4 1/2 to 1 inch thick 16 to 18 inch long wooden boards (table legs)
  • 4 table surface boards (length depends on printing size needs) 
  • A glass panel as large as table surface boards
  • 16 or more 4-inch long nails 
  • Hammer 
  • A halogen lamp or other form of UV light 
  • Sandpaper
  • Glass glue (optional) 

Step 1: Assemble the Wooden Frame 

Gather the wooden boards. Make sure the table surface stands parallel to the floor. If it doesn't, you may need to flatten the top of the table leg boards a bit. 

Once that's done, start assembling your table. Nail the table leg boards to the table surface boards. Nail the table surface boards together so they form a flat surface. 

Step 2: Attach the Glass Panel 

The glass panel should sit firmly on top of the table by itself. But if you want it extra secure, you can glue it to the wooden frame.

Make sure the glue stays above the wooden boards. You don't want the glue to affect your printing job. 

Step 3: Placing the Halogen Lamp 

Your halogen lamp should go under the table. The screen will sit on top of the table when you use it. 

Using Your DIY Exposure Unit 

Tape your design image to the top of the glass face down. Place your photo emulsion-coated silk screen on top of the design image. Place something flat and heavy on top of the silk screen so that it stays down. 

Put the halogen lamp under the table and turn it on. In around 30 seconds to a minute, the photo emulsion above the design image should burn away. 

Remove the heavy object above the silk screen. Then lift the silk screen. Your silk screen should now be ready for ink printing. 

Try Our Screen Printing Shop 

Now that you've completed your DIY print exposure unit, have fun! You should be able to create as many burnt silk screens as you want using this method. With these screens, you can create a huge amount of printed products. 

After purchasing screen printing equipment, you can visit our screen printing shop for our various paints, photo emulsion, silk screen construction equipment, and more. And don't worry if you're not in our local area; we ship domestically and internationally. 

Plus, we also offer custom burnt silk screens if you don't want to build an exposure unit. Check them out on this page