Acrylic (cast vs extruded)

Acrylic (PMMA, often sold as Plexiglas, Acrylite or Lucite) is a clear or colored plastic sheet. Sign shops use it for channel letter faces, flat cut letters, panels and displays. It comes in two kinds, cast and extruded, which look alike but cut differently.

Cast and extruded

	Cast acrylic	Extruded acrylic
How it is made	Liquid poured between plates and cured	Pushed through rollers as a continuous sheet
Thickness	Can vary across a sheet, sometimes by about 10%	More even
On a router	Cuts cleanly, less melting	Softer, can melt and re-weld behind the bit if feeds are too slow
On a laser	Engraving turns frosty white	Engraving stays mostly clear; cut edges flame-polish well
Price	Usually higher	Usually lower

These are general differences; brands and grades vary, so check your supplier's data sheet.

Sizes and thicknesses

Full sheets are usually 48 × 96 in, and many suppliers also sell 48 × 48 in and smaller cut pieces. For channel letter faces, translucent white about 3/16 in thick is common. Flat cut letters often use 1/4 in to 1/2 in, and clear or colored sheets come from about 1/8 in up.

Cutting acrylic for signs

Router: single-flute (O-flute) bits made for plastics clear chips well and help stop melting. Keep the feed rate up so the bit does not rub.
Laser: CO2 lasers cut acrylic with a polished edge. Thicker sheets need more passes or more power.
Protective film: leave the film on while cutting, to protect the face from scratches.

Acrylic is one of the pricier materials in a sign job, so how tightly the parts are nested shows up quickly in material cost. More in reducing acrylic waste on a CNC router.

How NestSigns handles it

NestSigns nests acrylic faces and letters by their real outlines onto full sheets and leftovers, keeps a separate stock list and price for each color and thickness, and sets the part spacing from your bit or laser kerf. See acrylic sheet nesting.

Try it on your own job. Open your artwork, pick a sheet, and see how many sheets you need. 20 free nesting runs, no credit card. After that, $14.99 per month, cancel anytime.
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