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HOW TO CUT PLASTIC 91

makers refer to this raw material as substrate. It’s available in a variety of sizes and thick-
nesses, in many colors: blue, red, orange, tan, black, brown, yellow . . . you name it.
PVC sheet goes by many trade names, such as Sintra, Celtec, Komatex, Trovicel, and
Versacel, but it’s probably easiest if you just ask for it by its generic expanded PVC or foamed
PVC moniker.

CHOICES IN SHEET THICKNESS
Sheets are commonly available in any of several millimeter sizes. Here are some of the more
common thicknesses:
• 3mm, or roughly 1/8″
• 6mm, or roughly 1/4″
• 10mm, or roughly 13/32″

The following table details the weight of a 12″ 12″ rigid expanded PVC sheet, at various
thicknesses. Comparable weight per square foot for acrylic plastic is also given; all weights are
representative, as some brands are lighter or heavier than others.

Thickness Weight (lb/sq ft)
Expanded PVC Acrylic

.080 (5/64″) .287 .547
.118 (1/8″, or 3mm) .429 .729
.197 (3/16″) .722 1.09
.236 (1/4″, or 6mm) .858 1.46
.393 (3/8″) 1.03 2.19
.500 (1/2″) 1.30 2.91

How to Cut Plastic

For more about saws and materials cutting in general, be sure to read Chapter 6, “Mechanical
FYI Construction Techniques.”

Soft and thin plastics (1/16″ or less) may be cut with a sharp utility knife. When cutting,
place a sheet of cardboard or art board on the table. This helps keep the knife from cutting
into the table, which could ruin the tabletop and dull the knife. Use a carpenter’s square or
metal rule when you need to cut a straight line. Prolong the blade’s life by using the rule
against the knife holder, and not by the blade.

CUTTING BY SCORING
Harder plastics can be cut in a variety of ways. When cutting acrylic plastic less than 3/16″
inch thick, one way is to use the score method (see Figure 9-3):

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