Photograv..grrr....

[Eric Allen]

I haven't been using my copy of Photograv lately, so now that I'm in a crunch, it's smacking me around. I have a background that pops up as black at the moment. When I save the bitmap in Corel it merges with the background with no way to opt out. The end effect is that I get a black background around my cutout pic, definitely not what I'm looking for. Anyone work with these two programs enough to remember how to cut out a pic and just get the part you want photograved with no or white background?

Ok, figured this out by changing the background in Corel that it merges with. It was black and just didn't show in the Corel file. Now, anyone have good settings for engraving the back of a mirror? I'm a tad rusty where pics are concerned.....

[Bill Cunningham]

I just use the generic Cherry setting.. It works for most everything

[Eric Allen]

I just use the generic Cherry setting.. It works for most everything

I should have specified, I meant speed and power I'm engraving on the back of the mirror, just want to take away the mirror surface so I can paint it in black.

[Anthony Welch]

Like Bill said use the "Cherry" settings, invert the art, engrave at the settings in your book for acrylic. Mine is 45watt as well, raster 100s/50p. You may have to tweak the settings to get through the mirrored backing. But this should get you close or engrave twice? Then next time use your tweaked setting, remember to write them down.

I am by no means an expert, just, this is the way I've found to do things.

[Frank Corker]

Eric each mirror is different. It's dependent on the surface coating that is put on the back of the mirror, sometimes the mirror is made for bathrooms and so it has a very thick coating or more than one coat over the silvering. This makes it a lot harder for the laser to break through. I have done about 30 mirrors, only about 4 have been identical. It's just experience.

Engrave with too little power and the image won't even break through the back coating, too much and there will be no chance that you can engrave it with a second or third run.

Never stop your engraving at the beginning or half way through, you will never be able to line it up in a month of Sundays and as a result of that, you will end up with a small ridge or line running through your picture.

I have a 45 watt Epilog and on mirrors I usually engrave at 33 power to 100 speed at 300 dpi, it seems to work for me but it won't for everyone.

[Eric Allen]

Sounds about right Frank, I was thinking it was low power. I'm using those full length mirrors that you can get for $6 or $7 here, they are lightly coated and easy to punch through and cut, but damned if I could remember a setting Hate to overpower it and loose detail. Those Stanley 12x12 ones from BORG are too much of a pain, those are very heavily coated, looked like there was a layer of copper or something last time I tried to use one. Many thanks to all

[Tim Bateson]

Eric, If you're using Epilog Driver 7.8, you may want to try the dithering options instead of PhotoGrav. I find it engraves a more realistic photo. Although I have not yet tried it on glass.

[Frank Tralongo]

Tim,
I'm just about to upgrade my epi driver. Had been playing with photograv 2 and because of the buying time frame got 3 for $10 bucks but I gotta say ver 3 stinks worse than ver 2. the settings are really screwy.
Do you have any example(s) you could post just using the epi drivers ?

Sorry to all didn't mean to hi-jack this post.

[Bill Cunningham]

I find a lot of the photograv laser settings are out to lunch.. I usually don't use them. Once I have processed the picture, I run it 'by feel'. Once you have had your laser for a while, you will pretty well know how different materials are going to react. I usually order mirror from the same glass supplier, and get a dozen or so of the popular sizes (8x10, 5x7, 12x12) that way I find the mirror is pretty consistent because they usually cut it all from the same large sheet. I find that mirror usually etches at the same settings I use for wood (i.e walnut etc..) I also find that if you try to 'hog it out' all in one pass, it will not look as well as if you did it in 2 or even three passes.

[Eric Allen]

Yeah, usually I remember this kind of thing, or have it in my notes. It was odd, because I know the last time I ran something it didn't take nearly as long, or as much power. Gonna have to do a bit of cutting to see if my laser is dying already. It's just out of warranty, that'd be about my timing... This ended up being 10 passes as I slowly increased power to get it right, took waaaay more than I thought it should, think the final was something like 50 speed and 100 power at 300 dpi. These are crappy mirrors, the finish on the back came off much easier the first time I thought...but this is a different style. The earlier work I did was line art, I'm thinking maybe the finish burned off easier because there were larger heat affected areas instead of black-white-black-white dithering you get with photograved pics.