Machines for cutting stencils: what to choose and how to use them

How to choose: start from the material, not from the machine

Three questions decide almost everything.

The three families of machines

For each one: what it cuts, what it doesn't, and how to make a stencil with it in practice.

Diode laser

Desktop lasers with a blue diode module, from a few watts to a few tens of watts of optical output

The most common home laser. It cuts by burning along a line, so it works on materials that absorb blue light: wood, card, felt, leather, dark opaque plastics. It is cheap to run and needs no cooling water, but it is slower than a CO2 laser on thick material, and transparent materials let the beam pass straight through.

Good for

• Card and cardstock, very quickly
• Thin plywood, basswood and veneer (thickness depends on power and number of passes)
• Felt, cork, vegetable-tanned leather
• Opaque or coloured PET film, with care
• Dark, opaque acrylic, thin

Not for

• Clear, white and blue acrylic: the manufacturer states the blue diode cannot cut them
• Clear PET film: most of the light goes through instead of cutting
• Metal sheet (a diode can mark coated metal, not cut a steel stencil)
• PVC and adhesive vinyl: never, with any laser (see safety)

Making a stencil with a diode laser

Stencil materials and how they behave

Card 0.3 mm

Cuts in one fast pass with low power. Edges turn slightly brown, the stencil is good for a few uses, then softens with paint. Not washable. Perfect for testing a design before cutting it in a better material.

Plywood or MDF 1–3 mm

Stiff, does not move under a roller, lasts a long time if you seal it with a coat of varnish or shellac. Edges come out dark and sooty: wipe them before the first use or they mark the paint. Thin bridges across the grain break easily.

PET / Mylar

Clear film does not cut well with a blue diode. Use coloured or opaque PET, or cover the film with paper masking tape so the tape absorbs the light; peel it off after cutting. Go slowly with power: PET melts and leaves a bead on the edge.

Realistic detail and bridges

The burned line is wider than the beam, and on wood the char eats into small details. On card 0.3 mm our engine uses 1.5 mm as the minimum detail; on plywood count on bridges of at least 2 mm, more if they run along the grain or if the stencil is large.

Setting up the file in StencilVector

1. 01Set the real width of the stencil in millimetres before downloading: the SVG comes out at that size, import it at 100 %.
2. 02Bridge width: 1.5 mm is fine for card; for plywood go to 2–3 mm (the slider goes up to 2 mm for stencils up to 150 mm wide, 3 mm up to 300 mm, 5 mm above).
3. 03If long thin parts flutter, raise Bridges per island or Structural stability rather than widening everything.
4. 04Download the SVG for the laser software; the PNG is a picture and needs tracing.

Typical problems

Islands (the centre of an O, the eye of a face) fall out

Fix: They need a bridge: check the bridge preview before downloading. In the laser software cut inner shapes first and the outer outline last, so nothing shifts during the job.

Bridges burn through or snap

Fix: Wider bridges, less power and two passes instead of one, air assist on. On wood, avoid bridges thinner than the grain can hold.

Scorch marks and flame on card

Fix: Air assist, honeycomb or raised bed, masking tape on top, and a faster speed with more passes.

Thin plywood warps and goes out of focus

Fix: Hold it flat with pins or magnets; refocus on the actual surface.

CO2 laser

Gas-tube lasers, desktop or cabinet, with water cooling

The workshop standard for stencils. Its wavelength is absorbed by clear plastics, so it cuts transparent PET and acrylic, and it is much faster on wood and MDF. In exchange it is bigger, needs cooling and proper fume extraction, and the tube is a consumable.

Good for

• Mylar / PET film, clear or coloured: the classic reusable stencil
• Clear and coloured acrylic, with a clean polished edge
• Plywood and MDF, thicker than a diode handles comfortably
• Card, paper, felt, leather

Not for

• Bare metal sheet (that is a job for fiber or industrial lasers)
• PVC and adhesive vinyl: never
• Polycarbonate and ABS: poor results and harmful fumes, avoid

Making a stencil with a CO2 laser

Stencil materials and how they behave

PET / Mylar 0.1–0.35 mm

The best stencil material for paint: washable with water or solvent, reusable many times, flexible enough for curved surfaces. Thinner film holds finer detail but curls more; thicker film lies flat but needs wider details.

Acrylic 1–3 mm

Rigid and very durable, for flat surfaces and repeated work. Does not follow curves. Clear acrylic lets you see the surface underneath while you place it.

MDF and plywood

Cuts faster and cleaner than with a diode. Same rule on the edges: wipe the soot and seal the surface if it will see a lot of wet paint.

Realistic detail and bridges

For PET 0.5 mm (mylar) the StencilVector engine uses 1.0 mm as minimum detail and minimum bridge, and warns below 1.4 mm. Thinner film can go a little finer; for daily use with a roller stay above those values.

Setting up the file in StencilVector

1. 01Real width in millimetres first, then bridges: the default bridge is 0.5 % of the width (1.5 mm on an A4, up to 4 mm on very large stencils).
2. 02For PET film 1.5 mm bridges are a good start; raise them to 2 mm if the stencil will be rolled or washed often.
3. 03Bridge shape: Filleted bridges spread the stress at the corners and tear less on film; Straight ones are the cleanest to paint around.
4. 04Open the stencil in Vector Studio and pick PET 0.5 mm (mylar): parts below the material minimum are flagged one by one.

Typical problems

Melted edges, a bead along the cut

Fix: Less power, more speed, two light passes. The edge should be clean, not glassy.

The film curls, lifts or welds back to the sheet

Fix: Tape it flat on the bed or hold it with pins, keep air assist moderate so it does not blow the film around.

Small parts move halfway through the job

Fix: Cut inner shapes first, outline last; check that every island has a bridge.

Strong smell

Fix: Extraction to the outside, always. PET is a common laser material, but its fumes are not to be breathed.

Blade cutters

Craft cutters (Cricut, Silhouette) and vinyl plotters

A small blade drags along the line. No fumes, no burning, no fire risk, and it is the only safe way to cut PVC and adhesive vinyl. It is ideal for thin flat materials; it struggles with very small closed shapes, tight corners and anything thick.

Good for

• Adhesive vinyl, for one-shot stencils on walls, glass, furniture
• Thin stencil film and Mylar
• PVC film and sheets: the right machine for them
• Card and paper
• Some craft cutters cut thin balsa and basswood with a dedicated knife blade (Cricut Knife Blade: Maker series, balsa up to about 2.4 mm)

Not for

• Thick or hard materials: plywood, MDF, acrylic
• Very fine details: the blade drags on tight curves and small holes

Making a stencil with a blade cutter

Stencil materials and how they behave

Adhesive vinyl

Sticks to the surface, so paint cannot creep underneath: the sharpest edge you can get, but usually one use. Remove it soon after painting. Use transfer tape to move it: the tape also holds the islands in place.

Stencil film / thin Mylar

Reusable and washable like laser-cut film. Thinner film cuts in one pass; thicker film may need more pressure or a second pass. Always do a test cut.

PVC film

Cut it only with a blade. It is common in stencil sheets sold for crafts: if the label says PVC or vinyl, it never goes in a laser.

Realistic detail and bridges

A blade does not like tiny holes and sharp inside corners: keep details a bit larger than you would on a laser and avoid hairline gaps. With adhesive vinyl and transfer tape, islands stay in position even with thin bridges, so you can keep bridges at the minimum.

Setting up the file in StencilVector

1. 01Set the real width: craft cutters have a limited cutting width, check the size before cutting.
2. 02Bridges 1.5 mm for film; with adhesive vinyl the minimum is enough.
3. 03Prefer Filleted bridges: rounded corners tear less under the blade than sharp ones.
4. 04Use the SVG and check the size after import: some programs assume a different resolution.

Typical problems

The film tears on corners

Fix: Slower speed, sharp blade, rounder shapes (Filleted bridges).

It doesn't cut through

Fix: More pressure or a second pass, after a test cut in a corner of the sheet.

The sheet slides on the mat

Fix: A mat that still grips; tape the edges of the film.

Small pieces are hard to weed

Fix: Weeding hook, and enough light; on vinyl, weed before applying transfer tape.

Material × machine at a glance

Indicative thicknesses for stencils, not machine limits. Always do a test cut on a scrap.

Setting up a stencil in StencilVector for your machine

The values below are the ones the engine actually uses.

Real size

Set the final width in millimetres before you download. Bridges and minimum details are calculated in millimetres on that size: the same file printed twice as big has bridges twice as wide.

Bridge width

Starts at 0.5 % of the stencil width, rounded to 0.5 mm, between 1.5 and 4 mm. You can set it from 1.5 mm up to 2 mm (stencils up to 150 mm wide), 3 mm (up to 300 mm) or 5 mm (larger).

Bridges per island

How many bridges hold each loose part. More bridges, sturdier stencil, slightly busier design. Raise it for wood and for stencils that will be washed often.

Structural stability

The engine keeps adding bridges until the sheet reaches this level. A high value suits thin film used many times.

Bridge shape

Straight, Filleted (rounded corners, tear less on film and under a blade) or Artistic (curves that follow the image).

Vector Studio

Choose the material (PET 0.5 mm mylar or 0.8 mm stainless steel): every part below that material's minimum detail is flagged, and you can move, widen or add bridges in millimetres.

Kerf: the width the laser removes

A laser removes a line of material, so every cut shape comes out slightly larger and every bridge slightly thinner than drawn. How much depends on machine, focus and material: measure it by cutting a 20 mm square and comparing hole and piece. If your kerf is large, raise the bridge width by that amount. A blade removes almost nothing.

Using the stencil: getting a clean edge

Most blurry edges come from too much paint, not from the stencil.

1. 01

   Hold it down

   A light mist of repositionable spray adhesive on the back, let it get tacky, then press the edges and bridges down. Low-tack tape on the outer border. Adhesive vinyl sticks by itself.

2. 02

   Spray paint

   Hold the can perpendicular, at the distance the paint maker recommends, and build up several light coats. One heavy coat creeps under the edges.

3. 03

   Roller

   Foam roller, little paint, roll off the excess on paper first. Light pressure, from the stencil towards the hole, not the other way round.

4. 04

   Brush or sponge

   Stencil brush or sponge almost dry, dabbed vertically, never brushed sideways under the edge.

5. 05

   Several colours

   One stencil per colour, all on sheets of the same size, with the same registration marks (corners or small holes in identical positions) so they line up. Lightest colour first, let each coat dry.

6. 06

   Clean and store

   Clean PET while the paint is fresh, with water or the paint's own solvent; store it flat. Card and wood: let them dry flat and wipe them.

Safety, without discounts

• Never put PVC or vinyl in a laser: it releases chlorine, which is toxic and turns into acid that corrodes the machine.
• If you don't know what a plastic is, don't laser it.
• Fume extraction to the outside for any laser, even with "safe" materials such as PET and wood.
• Goggles for the laser's wavelength, and never leave a laser running unattended: card and wood can catch fire.
• Blades: change them when they tear instead of cut, and keep fingers off the carriage.

Machines we recommend

By family, with what each brand is good for when the goal is stencils. Before any of them: if you need few stencils, Cuttalo.com cuts them for you.

Some links are affiliate links: if you buy, we receive a commission at no extra cost to you. We only recommend what makes sense for stencils, and we name the limits of each machine as well as its strengths. Brands without a link are described the same way.

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