marble...

[jeremy haneca]

i have done a brief search and cannot come up with and difinative answer.. im trying to enrgrave photos on marlble. the problem is that im not getting much definition, im running at 300 dpi, and at the suggeted photograv settings... i know from what ive heard that these can be completely off. anyone have any magic answer to giving more contrast in shaded areas like the face/ cheeks? the suggested settings for my 30w was 100p/63s. is it a simple solution like adjusting those 2 settings? when i adjusted the black level in photograv it made the dark parts darker, but still didnt give definition like the simulation... i can see all the dots im supposed to get, and im not getting them.

[Craig Hogarth]

power is too high. On my 35 watt, i run at 70p/100sp.

[Ken Smith]

I'm not too sure about Marble, but for Granite, using my V460-50w, I run 15 power, 100 speed, and 250ppi. Photos come out great.

I don't use PhotoGrav. I've created a PhotoShop action that does a great job of prepping images. It's a balance of Levels/Contrast/Unsharp mask filter.

:o
Ken Smith
ULS V460-50w
ULS M300-25w

[Don Gares]

I have found marble to be very forgiving as far as power goes. On my 40 watt machine I have engraved photographs at 100 speed with the power anywhere from 25 to 65 without any noticeable difference.

Don

[Bill Cunningham]

Yup marble is 'very' forgiving.. As a matter of fact, you don't even need photograv for marble. I have etched marble @ 600 dpi using only the halftone generated by the print driver. I recently ran into a situation, where I ordered 'Laser Grade Marble' and it wasn't marble at all.. It was a very high quality black stone, but not marble.. I called them, and they send me another piece to replace the mistake, which was also not marble.. The supplier was under the impression that this material was marble and it was not.. Marble takes a lot more power to etch than granite, and when the supplier of this material told me he usually etches it at 2-3 times the speed I was using, I knew for sure he wasn't etching marble.. If you put a drop of muriatic acid on the polished face of the stone that was just done with poor contrast, it will tell you for sure! If the acid hits the polished surface of marble, it will marr the surface and trying to wipe it off will only make thing worse.. If the acid has no effect, then it's not marble, but just something that is black, hard, and will do the job if you hit it faster.. I finally etched this stuff at 97 sp and 100 power, and a layer of titanium white oil paint rubbed in well to brighten it up..(it etched grey like granite) Real Marble (black, brown, green..etc) I was doing at 35-40 speed 600 dpi, 100 power and sometimes did it twice to brighten right it up.. Marble will need no whitening to brighten it up , it bleaches nice, and takes a wack of a lot more power to etch than granite..

[Gary Hair]

Marble takes a lot more power to etch than granite

That's funny, I found the exact opposite to be true. I run granite at slow speed and high power, marble at low power and high speed.

Gary

[Tom Cullen]

Guess i will add my fiddy cents worth in . I also have a 30watt laser and had the same issues with my marble. I pretty much just do black marble and have had a lot of success with photo reproduction. What I do is size the image to the size I need , keep it at 600 DPI , no more than that and not under 300 DPI. I convert the image to grey scale and save it as a bit map. Import the image into photograv, I use the manual settings, set the DPI to what you saved it at ( in my case 600DPI ) set your params to black marble . Now you will have to play this part by eye, adjust your photo through each manual step to get it as close to the original as you can. Even though you may end up with a certain speed and power setting, I save the image and use my own. I run mine at 100 power and 22-25 speed. It takes about 45mins to get a tile done but so far that has been the perfect settings for me with little or no quality issues.

Hope this helps and dosen't further confuse.
Tom

[Bill Cunningham]

H.D. stocks a 'brown' marble "empador lite?".. If you spend some time rooting through the boxes, you can find some without a lot of 'marbling'.. This stuff provides excellent photographs, just about goof proof, and you don't even need photograv to prepare the photo
The pic attached, is just a test sheet etched from 300 to 600 dpi and the white you see is the actual colour of the etched marble, no whitening should be needed with marble.. It's a little small. but the photo in the lower left was etched at 600 dpi using only the print driver (no photograv) and in real life, looks exactly like a b/w photo

[jeremy haneca]

ive been off in my lala land unable to reply for a while but i think ive ironed out my "sweet spot" on my laser, its a pretty good setting for my laser anyways. im running 60s/27p but im not finding it very forgiving either tho. i noticed a difference from 30 - 27%; enough to make me stick with 27.... i am one with my laser....lol

[Jay Beller]

I love working with marble and have the scars to prove it.

The key for me was finding great product. I thought Hard Laser Grade from Lasersketch was the best until I went to local tile stores and found a Non-vein (NV) solid black tile from China. Weighs about 6 pounds for a 12x12, but engraving is gorgeous. Whites are white!

Seems like opinions for speed and power settings are all over the place. I have found that slow works best (15s 45p on a 35w). I recommend taking a tile and conducting a test of various speed/power settings. I use an image of a zebra with a wide range of shades. I prepare at 300 dpi and PhotoGrav using their BLKMARBL parameters. I then print about 25 1" images with the settings I used. That way, I can observe the results and see the settings I used.

Here are photos - The zebra, a 6x6 Lasersketch and my favorite NV Tile

[Frank Corker]

Beautiful work. That tile being really black gives a great contrast.

[Bill Cunningham]

My rule of thumb.. If it etches 'white' it's marble.. If it etches 'gray' it ain't, no matter what they call it... If it etches white (marble) Higher power slower speed.. If it etches gray (mystery stone) Higher speed, lower power.. A drop of acid on the back or on a piece of scrap, will tell you if it's marble or not..Marble reacts to acid, and not in a good way..

[Ross Lowry]

I have a 45 watt Epilog mini and I run marble at the recommended setting which is 100 power and 20 speed and I have never had a problem with the image?
I do run the image through photograv though.

[Jay Beller]

I still contend that with the range of products we're calling marble, it's still worth taking 1 tile and printing 10-25 one-inch images (like my zebra) at different speeds and power. This is one group of materials for which each of us needs to find our own "best settings"

[Mike Christen]

Hi Jay

Maybe you could share the zebra photo, looks like a good test picture. I too have marble(?) from lasersketch that does not seem to do well.

Are you using any fill after engraving? Those pieces are beautiful.

Thanks
Mike

[Jay Beller]

Mike - that's natural engraving, no fill (except text on the image of Sydney). If you cannot grab the zebra image from the forum, send me a private message with your email address. I'd be happy to send the zebra. Let me know if you want it preprocessed with PhotoGrav.

[Frank Corker]

I think it looks better when it hasn't been filled. I might actually be in the minority here when it comes to filling granite and marble after it has been engraved, but in my opinion (OWIAETH) if I wanted a solid white finish it would be better having it screen printed. Now what would be the point of that? People pay to have something that is unusual, engraving of an image is unusual to the regular shop shelves, why then go and make it look like a transfer.

[Dee Gallo]

a SLA? Can we all use this now? Seems like we should, since we all have opinions (OWIAETH).

Frank, your eyes are mesmerizing.....

[Frank Corker]

ahh but my SLA is explained below! - in blue

[Marc Myer]

I just picked up some interesting marble tile at HomeDepot on sale. It's a sand color with lots of striations. But they were only $3 each--couldn't pass up the deal.
I engrave architectural images, and thought this might be a good medium to try. Normally I use black granite.

Have you had any success engraving and then colorfilling light marble? Do you use black oil paint?

[Mike Mackenzie]

Here is a picture of white marble that was colored black after engraving. All I did was to spray paint the tile wait 10 minutes and wipe off the excess with a rag and paint thinner.

[Stanley Waldrup]

Jay can you tell us more about the Marble

[Jay Beller]

I think it's imported from China and known as NV (no vein) Absolute Black.

The distributor here in New York has a web site http://www.estoneusa.com/

At 6 pounds per tile, I expect it's too heavy to ship around the country, but if you can work through communication challenges, you may want to call and ask if there are distributors of the Estone Absolute Black elsewhere in the country.

[Phil Garcia]

Yes, Jay tells us more about the marble. That work is fantastic. Some of the best I have ever seen.