Cast and extruded acrylic are both PMMA but are made differently. That difference can affect thickness and engraving. Knowing the variant helps when designing a fitted part or a filled logo.
A cutting contour or an engraved area?
For simple cutting, consider thickness, colour, edge and price. Area engraving works on the surface, where the variants can produce different contrast. Cast acrylic is often chosen for a clear filled engraving, although colour and surface also matter.
Use the operations offered for the specific product. A sample shows its colour and surface; an engraved trial piece shows your logo in that variant.
Consistent thickness does not automatically mean a good fit
Actual thickness can vary within the stated tolerance. The laser also removes material along the cutting path. Designing solely for the nominal thickness can produce a joint that is too tight or loose.
For a snap fit or sliding joint, try several size variants. Read about fits in acrylic.
Compare the product you will order
Not every colour or finish is available in both manufacturing methods. Compare clear acrylic and clear extruded acrylic XT by product properties and available thicknesses.
Choose for the window, engraving or joint you are making rather than treating one variant as the default for every design.