Masking

 

Menu




















Masks - Not Just for Halloween!

The General Idea...

The general idea behind the mask (or resist) is pretty simple - if it isn't covered it's going to get blasted and carved. But the types of resist and how they are applied are varied and are limited only by your creativity and imagination. This, for me anyway, is the challenge and fun! This is what really adds that something special to your art.

The Process

A mask (resist) is applied to the glass surface and selected areas are cut out and removed. The areas not covered by the mask are blasted, leaving them "frosted", carved or etched.

I use the terms mask and masking and resist interchangeably.

Resist Materials

There are many types of resist materials available - and some that you can create for yourself. I will cover a few of the types that I have used and few that might seem a little surprising to you!

Contact Brand Shelf Paper

The most common for simple glass work is plain old Contact brand self-adhesive shelf paper! It will take 2 layers for most work - more if you're really going to be doing a lot of staging (covered next) or deep cutting. I strongly recommend the plain white - as you might be drawing on it and the patterned or clear doesn't lend itself to well to seeing your design.

Buttercut

When I first began working with stone, I visited my local cemetery headstone maker and purchased a 1/16 inch rubber matting type resist called Buttercut.. It is a tough rubber-like matting with adhesive on one side. It adheres well to smooth flat stone and holds up extremely well when blasting with crushed garnet or silicone carbide.

Buttercut is available through some stained glass shops or glass supply shops. It cuts like running a knife through butter - thus the name. It applies very easily on slightly textured surfaces and holds up well to the abrasives. This works well for stone or cutting very deeply (3/16 inch or more ) in to glass. Generally, you won't require this for simple glass engraving/carving work.

Photo Resist

It is a photo sensitive material that comes in thickness from about 3 mil to 10 mil. It works like developing a photo graph in that you expose the material to ultraviolet light with a mask of the design you want placed face down on top of the photo resist material. Once exposed, you wash out the material with a high pressure nozzle which attached to your sink. The mask requires about an hour drying time (hey, you can mircowave it or get out the hairdryer which works well too) and then you apply it to your glass with special masking adhesive.

Photo resist work wonderfully well. The drawback here is the expense. It's not for the mildly curious but won't put you in debt either. For under $350 you can get all set up with a nice beginning supply of photo resist materials from Rayzist (see Suppliers section).
.
I use this product for putting names on champagne glasses, doing very intricate designs and reproducing pen and ink drawings on glass. It is an amazing product and with a little practice you can achieve outstanding results - even on rocks!. Highly recommended by the glass guy.

Creative Masks

For the more unusual and create approach - try a few things on your own. One I found that works quite well is using Scribbles, a fabric paint. I have used it on glass and stone with super results. It takes about 24 hours to dry, but you can paint in on using the very small tip of the paint bottle, or you can spread it over a surface and cut it with an exact-o blade to create other designs. I found that this is easy for my grade school kids to use in making their own designs as it does not require using a sharp blade.
This design was done with Scribbles. The left side is with the Scribbles on the surface. I drew the design on the back and traced with Scribbles on the top. The right side is the piece after blasting. It leaves a great natural look.

Another method is to use spray glue to adhere masks to glass. I have used various types of lace to add classy touches to carvings of long stem roses. It looks super! As you can begin to see - there just isn't any limit to your imagination when it comes to masks. Have you seen the little plastic confetti that is shaped like hearts, stars, or any number of shapes? You can find them in party stores and with a little glue, pop them right on the glass and blast over them.

Not everything that seems like a good idea works however, so be patient. I tried using the embossing templates you find in stamp/art stores. They look brass in color and you use a fine ball tipped pointer to emboss paper with them. I put one under the blaster and it warped something horrid! The abrasive actually pounded the metal into a dish shape -- well, so much for that try. But don't give up and keep looking everywhere you go. I've found dozens of things that work. Craft stores and fabric stores are great places to find new and creative materials.

Applying Resist

By following the step below you will be able to apply contact paper to class and cut your first design. This process allows you to either draw a design on or create one on your computer or from a picture and apply it to the masking.

Tools Required

  • Glass to etch
  • Glass cleaner
  • Very sharp exact-o blade(s)
  • Self adhesive shelving Contact paper - preferably white
  • A design
  • Spray glue (depending on how design is applied)

Application Steps

  1. Cut the glass to the size you want it before blasting - one slip with the glass cutter after all the work on blasting is very disappointing
  2. Use glass cleaner and carefully clean the area to be etched.
  3. Cut TWO pieces of Contact paper to completely cover the surface of the glass (blasting sprays a large area and all front areas must be covered to protect it from accidental etching)
  4. Carefully place the first piece of Contact paper over the area to be blasted. Using the back of your finger nails or a firm object, burnish (rub down) the entire area of Contact paper to ensure it is securely attached to the glass and no air bubbles exist.
  5. Lay the second piece over the first following the same procedure. Blasting can go through one piece very easily and will mar the surface.
  6. Apply your design. You can either draw directly on the Contact paper, or create a design on the computer and spray glue it down onto the Contact paper. Be sure it is exactly where you want it - you may get only one chance!
  7. Using a very sharp exact-o blade, cut out the pieces in the areas you want to be etched. Remove the pieces and burnish around the edges where each piece was removed to ensure it is securely attached to the glass. Blasting is done with great air pressure. Loose Contact paper will blow up causing fogging outside the lines of your design.
  8. Cover any uncovered areas with masking tape to protect it from the blasting spray. Don't worry about removing the unused portion of the paper mask.

Stage Blasting

Blasting is also done in stages. A stage is one time under the gun. What I mean is that you can arrange (or stage) blasting to get different depths cut into the glass. If you can imagine a tiny dart board target, only 3 inches across, with concentric circles, it will help explain staging. If remove only the dot in the center and blast it - that is stage one. Now if you remove the next inside concentric ring (which surrounds the dot you just blasted) and blast it, you have just done stage 2. The results is that the center dot is now blasted a little deeper with the second pass and the ring you just exposed has been blasted once. You actually are blasting the dot in the center twice at this time. The pattern that results is a staged effect. If you continue to do this which each ring working from the center out, you will have a multi-staged carving. The results will look a little like a funnel done in steps, with the dot in the center having been basted with each consecutive stage, and each ring blasted an additional time for each new ring you removed. It leave a stair step look, but with each ring clearly visible and differentiated by the depth from the rings on either side.

This how I layer feathers in a wing, or petals on a flower. By removing one at a time, I can create depth differences between them, giving the illusion of separation and individuality. You don't need to entirely blast the previous step (or stage) -- just getting the edges that are touching the next piece is good enough to leave a visual line between the two.