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sasha
11-02-2005, 4:08 PM
Would anyone be willing to post some suggestions on preparing a photo for engraving? We are custom furniture makers, so everything is engraved into wood. We primarily use out laser for cutting - the engraving is mostly a minor part of our business.

We have photoshop and corel draw, but not PhotoGrav. Is it possble to have good results without PhotoGrav?

I would very much appreciate some suggsetions about what type of software adjustments will make a photo look better when engraved.

Thanks,
Sasha

Nick Adams
11-02-2005, 5:20 PM
Is it possble to have good results without PhotoGrav?

Yes very much so, Photograv is just basically a shortcut alot use to get good results without the time needed to visually adjust most photos.

i will edit this shortly with some tips/techs to help. busy atm though.

Shaddy Dedmore
11-02-2005, 11:43 PM
There are a few things you can try... one is to just convert to grey scale and see how it goes. Some will look OK. Choose something like 200-300 DPI resolution.

Another is to tweak before hand, By increasing contrast, and by sharpening. You might have to lighten or darken as well. Practice practice practice.

Now you might do the above, and also convert to Black and White, using diffusion. I was told Stucki and Floyd-steinburg work the best. This basically converts it to little dots. Photograv does all this, but more smartly.

One tip for the black and white method, and photograv, is to make sure you have the picture sized correctly before doing it. Once it's a series of dots, resizing screws it up.

Shaddy

Bruce Volden
11-03-2005, 7:23 AM
Shash, Along with the photo set up it would help to know what type of wood you plan on engraving into. I usually avoid any oak due to open grain, etc.Bruce

Nick Adams
11-03-2005, 8:02 AM
Original Image
http://www.newtech-computers.com/Sawmill_Photo/1
Color to Greyscale at 300DPI
http://www.newtech-computers.com/Sawmill_Photo/2
Increased Brightness in Photoshop by 69% to highlight detail
http://www.newtech-computers.com/Sawmill_Photo/3

Image converted from JPEG to Bitmap in PS using DIffusion Dithering.

http://www.newtech-computers.com/Sawmill_Photo/PSdiffdither.bmp

Same image processed in Photograve

http://www.newtech-computers.com/Sawmill_Photo/PG.BMP

Adjusting threshold and contrast while working with the brighter PS image one could highlight the edges better. However you would be doing the same thing photograve does in 3 minutes or less. Photograv was able to process a 30in by 20 in photo for a piece of marble in about 4 minutes on my machine. For me to process the image in PS would have taken me around an hour to get the detail it deserved.


As you can see It can be done. And I could make the Photoshop picture much closer to the Photograved Photo. However for the amount of time spent doing the work Photograv is worth it even if you can just pay the program off after breaking even on a few jobs.

My time working with artwork is 60 per hour.
Photograve saves me an average of 25 minutes per Lasered Photo roughly.
Not in laser time but rather design/edit time.

I would engrave all of these but I am not in a possition to do that atm. Customer work going out steady all week.

I will check back to keep an eye on the thread.

Joe Pelonio
11-03-2005, 8:59 AM
Nick,

Good info and nice work. Just want to add, best to scan in position that will be used to engrave, rather than rotate the image later. When engraving on black or dark tile like marble/granite add the step of
inverting image (looks like photo negative). Finally, Corel Photo Paint and much of the software that comes with your digital camera will do some of the same as photoshop and photograv, but not as well and not as easily, and time is money. I too charge $60/hr but to keep competetive you want to minimize that time, plus you'll have time to do more jobs.

Nick Adams
11-03-2005, 9:28 AM
I agree with Joe.

All of my artwork is sent to me in digital format (non scaned originals). Or I charge $45 per hour to digitaze thier logo. After which they can purchase the vector reproduction for $75 on a CD. Containing CDR, AI,and EPS versions.

By doing this I limit my scanning to some sublimation work. but even at that I bet I only have to do 2 scans a month. And I have yet to loss a customer with these guidlines. SOme of them dont like that they need to have it converted but I push it a little with the fact that after it is converted any printing shop can then use it for flyers brochures and advertisments with minimal editing.

sasha
11-03-2005, 11:28 AM
Thanks very much for the helpful advice. I think that we should probably just purchase PhotoGrav and save a lot of time and effort. It's nice to know that we could do it with the tool in house, though.

Shaddy Dedmore
11-03-2005, 1:41 PM
Don't forget to try it first. It's quite possible your driver will do a fair enough job on some photos.

try some alder, nice contrast. just make the photo greyscale and see what happens. Items with a lot of shading and a lot of different colors (well, levels of grey) would need to be dithered, but if there isn't a lot, it might work just fine. Take a small piece of scrap of whatever wood you use most and give it a try. Sure, photograv makes it easy and quick, but you might get acceptable results without spending the dough.

What kind of photo's will you be engraving? That's the most important Q. If you will be doing photos, like of people and things, then Dithering will probably be the way to go eventually. But text and line art and some landscape stuff wouldn't gain anything by dithering.

Just my .02 I have photograv, but I only use it about 50% or less of the time. So I was just making sure you needed it before you shelled out the money.

Shaddy