ProStencil offers two standard stencil materials. One is a 4 mil vinyl and the other
is a 22 mil rubber based material. We have evaluated many others over the years
and these are the two that we have found that best serves our needs. We also can
offer a very heavy duty 52 mil rubber stencil material that is most commonly used
in making grave markers. It should be noted, however that we have sandblasted lots
of stone satisfactorily using the 22 mil rubber material.
Characteristics of a good stencil material.
A good stencil material should be:
- Capable of standing up to the job. This means it that if used as a sandblast resist
it should hold up as a protective material during the sandblasting without breakdown
(also called burning through). If it breaks down it will cause sandblast specks
or overspray. If used for painting or other decorative processes, it should hold
up for the time required while being used. It is always preferable to first try
- Have adequate self-adhesive qualities to stay in place during the entire process.
- Be easy to apply
- Be easily removed at the end of the process. High performance ( 2 mil ) vinyl can
be applied easily, and may even work for your process, but it has an adhesive that
is designed to last outdoors for about seven years. Needless to say, you definitely
do not want to be trying to remove this vinyl after sandblasting or painting.
When do you use vinyl versus rubber?
The 4 mil vinyl is normally used for single stage or shaded sandblasting. It can
also be used for dimensional sandblasting if it is not going to be very deep – such
as on tempered glass – and at a lower pressure. It is also appropriate for decorative
painting. The 22 mil rubber material is appropriate for sandblasting on stone, tile,
wood and most dimensional sandblasting. It will withstand higher pressures or longer
blasting times before breaking down. The disadvantage to the 22 mil material is
due to the fact that because it is thicker it is harder to feel how deep you have
Other vinyl thicknesses are also available but ProStencil has chosen not to offer
them. Thicker vinyl (often blue or green in color) comes in a variety of thicknesses
including 10 mil, 15 mil and 25 mil. They are usually fine for flat surfaces but
vinyl does not like to conform to irregular surfaces. Thus, it tries to pull up
from irregular surfaces creating the likelihood of problems from overspray or bleeding
paint under the stencil. Sandblasting some materials, such as wood and stone, generates
a lot of dust. Any dust that can reach the adhesive back of the stencil will result
in that area to no longer adhere to the piece you are sandblasting which compounds
the problem. If used on irregular surfaces such as stone, they also tend to crack
when going over ridges. These vinyls also do not seem to have the same adhesive
qualities as the rubber stencil material which makes them want to release or not
hold as well. This can result in sandblasting or paint where it is not wanted.
When working on compound curved surfaces, the rubber resist is easier to use because
it does stretch. You just want to be certain that it does not stretch so much that
it adversely distorts the image. Vinyl can be used for such purposes but is much
more time consuming and difficult. Since it does not stretch, it must be applied
in very small sections and likely will need to be slit to make it lay down. It is
difficult to apply text in a straight line using vinyl on a compound surface. Examples
of common items that may be sandblasted that may have compound curves include coffee
mugs, vases, and wine or champagne glasses.
For us for now, the two materials we offer seem to work for about every application.
Stencil sizes Available
Stencil materials only are available in certain roll widths. The 4 mil vinyl comes
in a 36 inch wide width which fits our plotter cutter. Theoretically it can cut
a stencil 341/2 inches wide x 150 feet long. Of course this is not practical. If
the stencil is fairly long and has straight lines, a roll feed feature is used to
keep the material running straight while it is being cut. We use the same 4 mil
vinyl but must have it custom cut and punched with holes to fit the rollfeed mechanism.
The machine that is used to punch these holes will only do up to 30 Inch wide rolls.
Thus, the size of vinyl stencil we can produce is governed both by the size of the
plotter/cutter that we use and also by whether it needs to be cut on material that
is setup for rollfeed.
The rubber resist is available in 30” widths.
What about stencil needs that are larger than these sizes?
This is not a problem as two or more stencils are created that are used to complete
the entire design. They are then registered, or plated, together to create the entire
design. The design is created as one piece in the computer and then sectioned into
sizes that can be cut. This allows them to perfectly go back together.