Thread: ? for lapping film users

when cutting large sheets down to fit smaller substrate what tech are folks using to get a clean straight cut ?

Blade along straightedge over cardboard or wood?

Abrasive side up or down ?

The PSA backed sheet i have is surprisingly tuff and my first cut from it was less than desirable.

Now I prefer not-PSA backed, and I use a normal cutter with a line.
Adbrasive downside on a cardboard, I use the line on the plastic back to write with a pencil and then cut.
Easy and fast to a clean sizeing.

I was using a paper cutter but the film kept bunching. Not I just use scissors.

I stuck my PSA film on marble tiles and then chamfered the edges with a metal object (screwdriver shank) to avoid an up-curled edge on the PSA from the factory cut. I was noticing that my edge would catch sometimes.

I use a large, sharp paper cutter(Guillotine Type), works just fine and cut 2-3 pieces at a time. Abrasive up and use the guide, for a square cut.

You don’t need PSA, just lap your substrate flat and smooth with a diamond plate. I use12X3 in. glass tiles from Lowes. After the first lap they are stuck on very well and you can do anything you would do on a stone.

Don’t waste money on Diamond grit film, Aluminum Oxide work quickly and very well… and last a long time.