Nice little video showing the basics for printing t-shirts.  Some of these basics include:

• Choosing a silk screen and where to get it
• How to apply light sensitive emulsion
• Light sources to burn the screen.  (They show an exposure unit like the one I built) CLICK HERE
• How to burn the screen
• Washing out the screen
• How to print the image on the t-shirt

As a bonus, the video will show you how to add LED lights and sounds to your t-shirt.

Check it out…

The cheap way to do a test wedge.  Take construction paper and do 4-5 different exposures.  Move the paper to expose more of the image each time.  At the end you will have 4-5 different exposure times.  Just pick the one that washes out the best and there ya go.

A lot of screen printers don’t follow the basics and create allot of grief for themselves including pin holes and emulsion breaking down during the print run.  Sure, they are coating screens and getting by but, they could be producing better screens in a much more efficient way.   I have put together 10 points to remember when coating your screens for screen printing.

1. Make sure you are using the right screen for the type of ink you are using and the item you are printing on.
2. The screen tension is tight. Tight screens will give you better prints and constancy.
3. Degrease the screens with “Simple Green” or a similar degreaser.
4. make sure the screen is completely dry prior to coating.
5. Mix your emulsion 2 hours prior to coating you screen.  This will let air bubbles bleed out so you don’t get pin holes.
6. Use the sharp edge of your scoop coater.
7. Coat the t-shirt side of the screen first and then the squeegee side.
8. Do one coat on each side.  Some people have other methods which involve more coats but this is what I do.
9. Dry your screen t-shirt side down.
10. make sure your screen is completely dry before you start printing.

I hope these tips help.  I didn’t go into much detail here but I may break them out in more detail in future posts.

as always, if you don’t have the book “How to Print T-Shirts for Fun and Profit! By: Scott Fresener” you should pick it up.

Have Fun..

Steve

Screen printing, Silk screening or serigraphy is a printmaking technique that creates a sharp edged image using a stencil. It is commonly used to print t-shirts, hats, tote bags, cd/dvd’s, posters, bumper stickers and a lot more. There are many materials and shapes that can be screen printed including ceramics, wood, plastics, glass, metals and paper.

The materials used in screen printing are very affordable and most of the equipment used can be built at home for very low cost.

The minimum items needed to screen print are:

• Screens
• Squeegees
• Scoop Coater
• Exposure light source
• Light sensitive emulsion
• Ink

Screens

Screen printing screens are wood or metal frames that are covered with a stretched fabric mesh attached to the frame. The mesh has holes in it that allow ink to flow through the screen. Mesh is rated in how many and what size the holes are. This will determine how much ink passes through the screen and onto the substrate or the material being printed.

Screens can be made or bought with the mesh pre-stretched and attached. Purchasing the pre-stretched screens are the best way to start.

Squeegees

Squeegees are used to push the ink through the screen and onto the substrate. The squeegee also sheers or cuts the ink so you end up with a sharp image. They come in many different sizes and durometers. Durometer is the unit of measure for the hardness of the rubber portion of the squeegee. They also come in square or rounded with metal or wood handles.

In my opinion, the best squeegee to start with would be a 70 durometer square blade. That will give good flexibility and the square edge will shear the ink.

Exposure light source

An exposure light source is any light that gives off ultra violet light (UV). Most light sources give off UV but some give off more than others. The more UV the light source gives off the faster you will expose the screen. Examples of light sources you can use are:

- The sun
- Unfiltered Black Lights
- Halogen Work Lights
- Mercury Vapor
- Metal Halide

The sun is the most inexpensive source but is hard to control exposure times. Many people start out with an $8 halogen work light from the local home improvement store.

Light Sensitive Emulsion

Emulsion is applied to the screen mesh and blocks all the holes except where the image is. The emulsion is sensitive to UV light and will harden or cure in the areas exposed by the UV. The art is printed on a clear or frosted sheet of plastic and then placed on a screen coated with emulsion. The light is blocked in the area of the art and remains uncured. The uncured emulsion can be washed out and the remaining cured emulsion will block the ink.

Ink

Ink comes in many different types depending on the material being printed on. The most common for t-shirt printing is Plastisol.   Plastisol isn’t ink at all. It is a liquid plastic that will harden or cure when exposed to heat of at least 320 degrees. Once the plastisol is cure the shirt can be worn. The other type of ink is water based that needs time to air dry. Water based inks will dry in the screen if you don’t keep the screen flooded where plastisol will never cure until exposed to heat. For frequent prints, some printers will leave plastisol in screens for months.

Scoop Coater

The scoop coater is used to apply the liquid emulsion to the screens

Part 2 coming soon