Short answer: Most custom stencils work best in 1/16 in. acrylic, which is thin enough to lay flat and give a sharp paint line, or 1/8 in. for large stencils and ones used as a router or tracing guide. Letters with enclosed shapes, like O, A, and R, need small bridges to hold the centers in place.

Why acrylic for a stencil

Paper and vinyl stencils are cheap but wear out after a few uses. Mylar is flexible and lasts longer but can curl. Acrylic is rigid, so it stays flat on a board or wall, it washes clean with soap and water, and laser-cut edges are smooth, so paint doesn't creep along a ragged edge. Clear acrylic also lets you see exactly where you're placing it.

Acrylic stencils are popular for painted wood signs, wall lettering, spray-painted parking and equipment marks, cookie and cake decorating, airbrushing, and tracing templates for crafts.

What thickness to choose

  • 1/16 in. (about 1.5 mm) for most painting stencils up to about 18 × 24 in. It's thin enough that a brush or sponge reaches right into the corners.
  • 1/8 in. (about 3 mm) for stencils larger than that, stencils you'll trace around with a pencil or knife, and floor or parking stencils that get stepped on.
  • Over 1/8 in. stops being a stencil and becomes a template. For router guides, see router and saw templates.

Thin acrylic is more flexible than you might expect but it's still rigid compared to Mylar, so it won't wrap around curves. For a curved surface, a vinyl or Mylar stencil is the better tool.

Bridges: keeping the islands in place

Any closed shape in your design, like the inside of an O, the triangle in an A, or the center of a ring, is an island. Cut it out as drawn and it falls away, leaving a blob where the letter should be. Bridges are thin strips that connect each island to the rest of the stencil.

  • Make bridges at least 0.06 in. (1.5 mm) wide in 1/16 in. sheet and about 0.1 in. in 1/8 in. sheet. Thinner bridges snap.
  • Put bridges where the eye expects a break, like the top and bottom of an O, or use a stencil font that already has them.
  • Two bridges per island holds it flat; one lets it flutter.

Tip: if you don't want bridges visible in the paint, use a two-layer stencil: the first paints the outlines, the second fills in the gaps. We can cut both from one drawing with matching registration holes.

How small can the details be?

Our lasers can cut very fine lines, but a stencil also has to survive being handled and washed. As a rule, keep openings and the plastic between them at least as wide as the sheet is thick. Text with letters under about 1/2 in. tall gets fragile in a stencil, and paint tends to bleed across tiny gaps. The smallest detail we can laser cut goes into more depth.

Preparing your file

Send vector artwork (SVG, DXF, AI, or PDF) with the cut lines as outlines, not filled shapes. If all you have is a photo or a JPG logo, convert it first; see how to convert an image to SVG, or send the image and describe what you want. Then upload the drawing for a price.

Using and cleaning an acrylic stencil

  • Hold it down with a light spray of repositionable adhesive or painter's tape on the corners.
  • Use a stippling motion or a nearly dry brush, working from the edge into the opening.
  • Clean water-based paints with warm soapy water. For oil or solvent paints, use mineral spirits sparingly and rinse right away; stronger solvents like acetone will craze or melt acrylic.

Questions

Can I use an acrylic stencil on cookies and cakes?

Many decorators do, with powdered sugar, cocoa, or royal icing. Clear sheet from major makers is stated to meet FDA 21 CFR 177.1010 for food contact, but colored sheet generally isn't, so cut food stencils from clear, read whether acrylic is food safe and keep the stencil just for food use.

Do stencils have to be clear?

No. Clear is easiest to position, but 1/8 in. stencils can be cut in colors such as red, blue, or yellow if you want them easy to find in a drawer.