When using non proofgrade material, do you cover it with tape to avoid scorching. If so what kind of tape. I thought I saw a YouTube video about it but can not find it now.
It all depends on the material and what you need to do post-processing.
Some folks just use magic erasers or other methods of removing the burn.
I tend to cover my non-proofgrade that isn’t masked.
The term you’re looking for is “masking”. You can use anything from masking tape to commercially made masking. I use the stuff linked below. You don’t have to mask anything, but it can help with a couple of things. If prevents smoke/soot from depositing on the material which can stain and be tough to clean up on some materials. For some projects I like the effect the smoke can give, other times I like a clean look so I mask. The smoke can often be cleaned so I skip masking when I don’t want to deal with peeling a million tiny pieces off. Smoke doesn’t effect things like acrylic so I don’t mask it for that reason, but I may if I need to protect it.
The second thing masking can do is protect the surface from laser burn or “flash back”. Flashback is when the laser heats up the metal tray and it leaves little burns on the back of the material.
Something to keep in mind is masking takes power to burn away and it will effect the outcome. If you mask using narrow tape and overlap it, the overlapped areas will be different then the other areas. There’s lots of other info out there about it if you want to give a quick search as well.
This discussion is good too
This might help you out with a lot of other items for non proof grade as well, such as clean up, measuring thickness, ect.
I have the type I use in there and a good trick to apply the masking tape too.
The “scorching” is an ash/smoke residue from what is vaporized that will wipe off with alcohol or ammonia. It’s not a burn.
Masking as the term implies will protect from that deposit, and it also creates a perfect painting mask if you plan to use a pigment in your design for contrast.
For a photo engrave most people don’t use a mask because the mask absorbs a little of the power and robs the image of the lightest tones.
Thank you everyone. Lots of great advise.
I engrave a lot of solid wood. If I don’t feel like sanding, I’ll use some wide blue painter’s tape to mask it. If sanding is not an issue, or I have to do a finish sand anyway, I’ll just engrave it and then sand off the smoke stain. It’s not tough at all.