Laser-engraving plywood that already has a varnish

Hello

I’ve been skip diving and am thinking of making a few things out of some lovely birch ply I rescued, would love to engrave a hefty pattern into it but it’s already been varnished - does this present an extraction / fumes issue @lasertechs?

Looks like the wood was only used indoors - so hopefully the varnish is nothing too strong. I could sand it off but because of the ply I’m a bit worried it’ll bust through the top veneer…

Not sure if you can use standard ply in the laser, it will probably have different adhesive in it than dedicated laser ply . An alternative would be to use one of the Cnc machines

It’s just for an engrave so top layer only would be hit by the laser, no glue in the lam I would imagine

I can’t see anything online that categorically says that laser engraving varnish is unsafe.
As to whether it is effective, I guess the only way to really be sure is to try it.
If you do try this, please let us know if the engraving results in soot on the mirror or nozzle that is hard to remove.