3M Perf Line Knifeless Tape - 50m3M Knifeless Perf Line Tape Trim your perforated window films, graphics, and much more without a knife. Faster, easier, and safer than trimming with a blade. Never risk cutting into a vehicle's paint again. 6. 35 mm (1 4 nominal) Width Use with perforated window film for perfect easy cuts every time. Translucent tape so you can see exactly where your line is and reposition the cut line as needed. Absolutely no residue! After trimmed leaves 1 8" gap to