Overspray Margin: How Much Sheet to Leave Around a Stencil

The overspray margin is the border of sheet left around the cut design to catch spray and roller creep. Leave enough that paint cannot reach the surface past the edge of the sheet, and not so much that the stencil becomes awkward to position, tape and store. The right margin depends on the method: a spray can needs more than a roller, and a large design needs more than a small one.

What the margin is doing

When you spray through a stencil, paint does not only land in the cut openings. A fine mist drifts sideways across the sheet and settles on whatever is just beyond its edge. The margin is the sacrificial border that takes that mist. If the sheet ends close to the design, the mist passes the edge and marks the wall, floor or fabric you wanted left clean.

The margin has a second job: it gives you somewhere to hold and tape. A stencil that is cut tight to its design leaves no clear sheet to press flat, so the edges of the openings lift first.

Margin and method

Spray paint throws the widest mist, so it asks for the widest margin, or masking tape and paper added outside the sheet for large areas. A roller deposits paint only where it touches, so a smaller margin is enough, provided you load the roller lightly and roll off the sheet rather than on to it. Brush and dabber work sits between the two.

For a large wall or floor design, do not rely on the stencil margin alone. Tape paper or film to the stencil edge and treat the sheet as the accurate part, not the whole mask.

Margin, bridges and islands

The margin protects the outside of the design. Bridges protect the inside. A bridge is a tie that holds an enclosed shape to the sheet, so the counter of an O or an A does not drop out; without it you have an island with nothing to hold it. Bridges are part of the cut, so they pass a little spray and leave a thin gap in the finished mark. That is normal, and it is the reason stencil lettering looks the way it does.

Margin and bridges interact through the sheet itself. The more of the sheet that is removed, the more flexible the stencil becomes, and the more a thin sheet will curl at the edges of large openings. A wide margin adds stiffness back around the cut area, which helps the stencil lie flat before you tape it down.

Material gauge

We cut from 14mil (0.35 mm) commercial Mylar, and also offer 7.5mil (0.19 mm). The thinner gauge conforms to curved and textured surfaces and is easier to lay flat against a wall; the heavier gauge holds its shape across large openings and survives more pulls, which is the number of times a stencil can be used. If you expect many pulls, or a large design with long open areas, the heavier sheet is the safer choice and the margin is easier to handle.

Kerf

The laser removes a thin strip along every cut line, called the kerf. It is small, but it is why very fine detail and very narrow bridges need to be drawn with some thickness. If your artwork has hairline gaps or ties, send it with the intended bridge widths and we will check how the cut will hold before it goes on the machine.

Choosing a margin for your job

Start from the method and the surface. Decide whether you will spray or roll, whether the area around the stencil can tolerate mist, and how large the design is. Then tell us the size you want for the finished mark and how much sheet you want around it. If you are unsure, say so when you upload the artwork and the proof will show the full sheet, design and margin together, before anything is cut.

To order a stencil cut from your own artwork, start from the custom stencils collection, where you can upload a logo or design and choose the Mylar gauge. For lettering, the same collection includes the online stencil designer.