Intro to Silkscreen Printing - Tips and Essentials

When approaching a project which requires silkscreen printing you have 2 main sets of choices

1) to use vinyl or to use photo emulsion
vinyl is faster and cheaper,  but requires a vinyl cutter for most projects
photo emulsion - can be done with chemicals in house or for about $25 from a vendor

2)  to use clamps or a "professional rig (a 4-way setup usually)
clamps are great for a single color and would be harder to line up for multiple colors
a 4-way set-up is great for multiple colors and requires a bit more practice to get a great print

supplies:
-vinyl
-silkscreen
-ink - in this case a water soluble screen printing ink from blick - ~$7.00 for a small and $21 for a large
-something to print onto like a tshirt or a canvas

Submitted by SFlettering for the Instructables Sponsorship Program

When using vinyl for a silkscreen project you are going to stick the vinyl to the silkscreen such that it must be a negative image. When preparing a vinyl stencil for silkscreening and using calligraphy your letters must be done in reverse

TIP: a great way to prep calligraphy style stencils for a silkscreen project is to design the calligraphy on the rear of the vinyl (it even has marks for lining up your writing) and to cut the stencil from the backside of the vinyl.

In the photo you can see an SF stencil for San Francisco done in black letter and showing the reverse view

BTW: I made it at Techshop http://techshop.ws

A vinyl stencil once drawn out and cut out from the vinyl will be placed on the outside (closer to fabric side) of the silkscreen. The view in this image is what it will look like on a tshirt and also shows the placement on the silkscreen. The vinyl stencil was placed in the middle of the screen and worked out well as you can see in steps 5 and 6 for printing.

also shown in this step are the contact paper to use to get the design off of the vinyl backing and onto the silkscreen and a ruler and knife which are essential when making your stencil.

Here you can see my first test print of the SF stencil onto a scrap tshirt. Notice how the upper part of the letter "S" is incomplete toward the top and how the letter "F" also has areas toward the top without ink.

2 things are going on here that are areas to improve
1) I flooded the silkscreen and ink got onto the upper part of the stencil resulting in an area that printed poorly toward the top of the stencil.
2) I needed to use more pressure and possibly more ink on the silk screen to get a better print

TIP: use more ink than you think necessary and you can always scrape it up and save it for later. 

here is the bottom view of the stencil where you can see the screen has flooded and has pooled ink on the letters "SF". 

2 ways to clean up the screen

1) remove screen and wash and clean
2) use several scrap pieces and make 4-5 prints until the extra ink creating the flooding issue is used up

Multiple prints onto scrap will clear the screen and remove the flooding issue. It took me 4 scrap pieces to clear the issue up 90%. Be well aware that if you attempt to use a tshirt that still has wet ink on it then the ink will stick to the bottom of the screen and show up when you do all future prints. 

TIP: If you get ink on the bottom of the screen consider taking the screen off the press and washing the entire screen before moving on with your printing

Here is my final print which required

1) more ink than expected (I used a blend of red and yellow on this print mixed very well)
2) 2 passes (when using clamp set-up) to get best overall quality
3) a clean surface that promotes contrast with the stencil and color chosen

a bit of luck resulting from practice and study of the techniques and tips for silkscreen printing with vinyl.