Test every material that differs meaningfully from standard paper, including coated stock, photographs, laminated sheets, labels, card stock, and synthetic media. Each material can affect blade resistance, edge quality, stack capacity, and the pressure needed to hold the sheet in place. Use a small sample to confirm that the cut remains square and free from tearing, crushing, or surface marking. Do not assume the advertised paper capacity applies to thicker or harder stock. If several materials are used in one job, test the thickest or most difficult combination. Record the successful stack size and settings near the trimmer so staff can repeat the process without forcing the blade or producing inconsistent finished pieces.