Engraving a Photo on Granite

[Michele Welch]

I have searched the forums and read numerous threads on processing photos to engrave on black granite, but the hitch in my getty up is that I'm using Photoshop/Illustrator and not Corel. I've got too much money invested in the Adobe products to dump them even though I know that Corel would probably be better for my laser applications. My main trade is graphic design and I utilize Adobe products for that work. I've seen several people mention choosing "Javis", "Floyd-Steinberg" or "Stucki" dithering process and I don't have those options within either of my programs. My photos just aren't looking great at all. At least not close to what I'm seeing people have posted online in several different forums. I have a 45w laser that I've gotten great results on other mediums, just not granite. I'm using the Absolute Black granite from Lowes which seems to be great on text/clipart. I've only had my laser since October, but am getting better everyday with practice, this granite just has me pulling my hair out.

Any help would be greatly appreciated. If you can point me to videos/tutorials that would be great as well. I've looked at several already that were mentioned in other posts, but those are mainly for Corel.

Thanks in advance for any help you can give me!!!

Michele

[Matt Turner (physics)]

It looks like you want the "diffusion" dither.

[Bruce Dorworth]

Search for the "Gold method" of picture prep. It uses Photoshop and is suppese to be pretty good.

Bruce

[Brian R Cain]

There's a plugin for Photoshop called Andromeda Screens. It's a filter that converts a gray scale image into a black and white one suitable for engraving, but unlike most black and white conversions allows you far greater control of the image. It gives the best output of any software I've encountered for engraving photos, and I've used them all.

If you go to their website http://www.andromeda.com/main/screens.php there's a link to a youtube video which shows the sort of things you can do. They also let you download a demo version.

[Dan Hintz]

Without a picture of your current results, we're all going to be guessing as to what the issue is. My guess would be you're not converting to a 1-bit image in the end and still trying to engrave it as a grayscale. All of the dithering options you mentioned are just that, options. One of them must be chosen (even if it's not given a name in your program of choice), but that's just part of the process in turning a grayscale image to 1-bit.

BTW, I use CorelDraw for layout/vector work, but when it comes to engraving (such as photos), I choose a raster program (PhotoShop, Paint.NET, etc.). I'm not a fan of Corel's version.

[Tim Bateson]

You didn't say which laser you are using. It can make a difference.

[Chuck Stone]

Adobe's dithering isn't very good at all. It allows you a couple of choices, but
no control over them. Imagine if your cloning brush wouldn't allow you to
change opacity or size .. or if the burn/dodge tool only worked on all levels
at the same time instead of separating highlights, midtones and shadows..
that's about how effective Photoshop's dithering options are. I can't use it.
Corel does allow you more control that way.

You don't need to get the latest version, but it is well worth picking
up Corel for the laser. For one thing (probably most important!) the help you
can get here will be Corel based, since that is the more common program for
laser use. I create in Photoshop too, but import into Corel for the
things that Adobe just doesn't do easily.

[stan kern]

i would like to see some posted results form both corel and adobe,i downloaded the demo plug in for adobe and will run some tests.
My photos are hit and miss ,really depends on the photo prep

[Larry Bratton]

Well Michael, if your into graphic design, you should know that if you have a crappy photo (low res) your gonna get a crappy result. You photo needs to be 200-300 ppi and engraved at the same resolution. I do prep in Photoshop CC, save as greyscale and then use another program called Photograv 3.0. The Gold method is a set of actions for use in Photoshop and can be downloaded from this site. Just do a search for it and you will find it. Works pretty well.
Remember also that any natural material such as granite can vary widely in quality. If you can find absolute black marble it is probably a better choice than granite tiles that come from the big box stores.

[Ben Dalton]

I've been engraving photos on black granite and wood for our business for 12 years, and I agree with Larry. Photograv works amazingly, and gives you a preview image that using the gold method doesn't (and customers really like have a proof). I think tweeking an image in photograv is very easy as well. Big problem most people have is that it costs around $400. If you've tapped a good market for granite engravings though, that will pay for itself very quickly and in my opinion is well worth the money. Photoshop can do amazing things with photos as well. I used to think the old GIGO rule had no exceptions, but if you can "smooth" out a grainy picture's pixels and pop the contrast of a photo, it's amazing the results you can get when running it through photograv. One of my favorite tools in photoshop is using a black and white adjustment layer. This lets you change the pictures black and white levels according to the colors in the photo... This can be very helpful as getting a good result on granite is all about contrast, and changing a photo's grayscale according to the color values can really make the contrast pop. The dodge and burn tools can also be very helpful for the same contrast reasons. Hope this helps a little....