Chris,

It really doesn't matter other than for the time it will take to engrave;

so give it enough power to get a complete raster of the image at the fastest speed without engraving into the glass.

Test it at several settings.

My settings are going to be different than yours and yours may be different than someone else with the same brand of machine because of many factors, like:

Laser tube condition,
condition of motion assembly (clean, dirty, worn)
the material you are engraving,
altitude,
weather conditions (humidity),
machine settings (dpi, lpi, etc)
condition of artwork (if applicable, B&W vs greyscale vs poor quality)
...

hth,

Chris,

I have a 30-watt laser and use Specialty Industries laser mask. My settings for completely burning away laser mask on glass, crystal and marble is 600 dpi, 35% speed and 95% power. This assures me that all of the mask and adhesive will be removed in one pass for blasting.

While we are on the subject, I've discovered something interesting using this process over the years. While lasering optical crystal through this mask material with the above settings I get a very high quality, non-grainy etch, even before I hit it with the blaster. I continue to hit all of my crystal with the sandblaster, but on occasion, I've been tempted to remove the mask and consider it done. The mask material must lessen or eliminate the fracturing effect that often happens with direct-to-crystal lasering.

Who are Specialty Industries? Do you have contact info?

Thanks,

OK, its "Show My Ignorance" time!

I still haven't use my sandblaster however I had assumed that you would only vector cut the mask and weed the parts to be blasted. Is there an advantage to rastering the blast area?

If there is a lot of very fine detail I can see the raster would be better and faster, but if its a large area it would seem weeding to be faster.

Guess I better get going on this, so much to learn, so little time. I'm still waiting for the contractor to finish my interior shop walls so I can hook everything up and get blasting.

Jim

David,

Tres cool! I learned something. I guess that's what its all about. Good info!

Jim

Chris,

I meant to say Specialty Tapes. I have a customer named Specialty Industries. Duh! Here is their info.

www.specialtytapes.net
800-545-8273

The stock item I use is a 6" x 25 Yd. roll. It is called Lazer's Edge, and is item CW-5764-625. $25 per roll if you buy onesies.

Jim,

When you vector the material, you will also create an outline that will end up being deeper than the rest of the blast. I would not recommend vectoring, but it can be done.

Another factor you need to take into account the amount of time you would spend weeding your image.

Chris,

I've seen duct tape and sometimes masking tape used in areas where etching isn't desired.

I suppose the thickness of the covering would depend on how hard you're going at it, with regard to nozzle pressure and the depth you're trying to achieve.