Line skips

[jbv]

“laser-safe” doesn’t always mean “cuts well”. This looks like a inclusion/void issue with the wood. Likely some kind of adhesive in the center layers that does not cut well.

here is a post I wrote a while back about inspecting plywood:

Inspecting thin plywood for voids and glue

I just posted this info as a response to a problem, and realized it could be helpful to others if I posted it on it’s own here. Sometimes plywood has hidden voids that are filled with glue. The laser often won’t cut all the way though the glue spots. Sometimes you can get through with another pass or two of the laser, or just finish the cut by hand with a hobby knife, but I find it best to just avoid the voids if possible by identifying where they are. I use this worklight from costco; with …

and another from @evansd2 that explains the issue a little better than I did:

Trick for inspecting plywood

The short version: use a really bright flashlight to shine through the plywood, and you can see inclusions and voids pretty easily, like x-ray vision. Longer: So, I’ve had a few cuts fail where inconsistency is in baltic birch plywood that I got at the local art store caused the pieces to not be fully cut. Upon inspection, it seems pretty obvious that there was a knot in the central sandwiched layer. So I took a bright flashlight and looked through my 1/8 inch plywood, and found some surprisi…