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James & Zelma Litzmann
08-11-2006, 5:07 PM
44581Hey guys, I am going to try to attach a picture of a 12 x 12 I did today to see if any of you can explain it in terms I can understand (simple) on what I am doing wrong. I brought it into CorelDraw (sized it), then to PhotoPaint (cut it out), then to Corel, then to PhotoGrave, then back to Corel. I used one of each parameters just to see what it would look like, none of them are good, the marble one is way too dark them some are way too washed out and they all have bands. I know it says I ran it at 30 power but I really ran it at 40 power, type "O". Once again, asking for help.

J&Z in
Huntsville, Tx

Guy Fuson
08-11-2006, 5:16 PM
I found that PhotoGrav does not work as good as Corel on Marble. I do alot of Marble using Corel.
You are using too much power. Also you need too invert the picture into a negative. I have a 50W Explorer and I vary between 13 & 20 on power & 60 - 100 on speed, Dpi 500 - PPi 500. Depending on your laser you may need to go to 600 on both Dpi & PPi.
Hope this helps.

James & Zelma Litzmann
08-13-2006, 8:44 AM
I tried to invert, but then her face was not rastered at all? And see I thought I wasn't using enough power, all these were done at the same time, the only one that looks washed out to me is the "Walnut" one, the ones on the top seem to be was too dark, but I will try less poser and see if it works. Thanks for you help.

J&Z (Psalms 18:2)
Inscriptions Of The Heart
Huntsville, Texas

Dave Jones
08-13-2006, 1:20 PM
The marble one looks close, just a bit dark and contrasty. Try selecting the marble as material, and then use the interactive mode in Photograv. That lets you adjust the brightness, the curves/linearity, the amount of edge enhancement, etc... Small changes can make a big difference. I find Photograv often defaults to too much edge enhancement.

Tom Cullen
08-13-2006, 2:32 PM
I'm not sure if this will help but I do quite a lot of marble and pretty much use the same settings ( my own) and get very good results. You can check my web site and have a look http://www.sandiegolaserengraving.com okay here's what I do , first I select the image and bring it into photoshop. I then size it and set the dpi at 300 then convert it to greyscale. I then play with the contrast and brightness until I have a good toned image and save it as an 8 bit bitmap. I then bring that into photograv from the file menu in the upper left select change dpi and change it to 300dpi. After that I use the interaction feature and set the settings that way with the original image on the left and the interactive on the right, I try to get them to match as close as I can.All I use is the first settings to set the black and then My settings for enhancing edges are usually 10/85 I leave all the rest as they are ( default) and at the end select my dpi and lens size and turn off the mirror button, at this point you can play with speed and power to further get your image to look as close to the original as you can. next say procede and check out the sample image using the buttons on top to move between the images . If you like it save it .... now heres the thing ,I import that image into Corel and keep the exact same size I saved it at and then tell it to print, in the print properties ( Pen settings) I choose the power setting of 80 and 25 speed ( same dpi 300).... I know this sounds a lot but it really works for me on my 35watt laserpro. I also realize you set the settings in the interactive window in photograv before saving the photo but even though I use my own it works out great for me.

Jackie Outten
08-13-2006, 5:31 PM
Don't forget to treat your marble with a little armour all before you engrave. Makes a real difference.

Jackie

Jason Sampson
08-13-2006, 5:34 PM
Jackie,

What's Amour All do for the marble?

Jason

Keith Outten
08-14-2006, 9:18 PM
Jason,

Coating your black marble with Armor All before you engrave will enhance the burn and give you whiter whites so to speak. It is a technique I worked on last year in an effort to improve the contrast when engraving black marble.

Try a test piece by coating one side of a tile with Armor All and engrave. The results are impressive.

.

Joe Pelonio
08-15-2006, 8:32 AM
Keith,

Have you ever contacted Armor All corporate to tell them about your discovery? Maybe they'll put you in a TV commercial or send you a free case for your innovation.

Daryl Barberousse
08-15-2006, 9:44 PM
I recently did my local county fair. Engraved over 60 marble plaques for the kids. I was an amour all sqwirting dude. Not sure I want to see or smell it for a long time. BTW, it did whiten the engraving....

Brent Brod
08-20-2006, 9:47 PM
I'd like to see a full day class on photo engraving. I would travel to get to it, and gladly pay a fee for materials and instructor. It would include using Photograv (I still don't get it), and engraving on wood, marble, granite, etc. Starting with the photos already cropped, but still in the original colors.

Have any of you seen radical differences in the power requirements for marble from different sources? The pre-cut stuff I got from Laserbits seems to require about 1/3 the power or less to get the same effect as the marble tile I bought from the tile store. My first attempt was washed out.

Tom Cullen
08-21-2006, 9:56 AM
Although I have never used it , I hear that laserbits black marble can be tricky compared to store bought. I have heard others mention that the power and speed settings would change because of the poor results they would get and the tones from black to white are not as good. I think you should stick with a store bought marble , find a good reliable supplier. The cost would certainly be less and your results more consistent.

Brent Brod
08-21-2006, 10:35 PM
The ready cut shapes are pretty handy, but it looks like it might be hard to get the hang of the settings. I wonder how difficult it is to work marble.