Photo Engrave from Illustrator

Beyond the Manual
#1

Hello all and Happy Holidays,

I could really use some assistance on this one as I am pulling my hair out and likely missing something obvious. Up until now I have done most of my photo engraves from files out of photoshop and never really brought anything into illustrator.

Well now I am trying to bring this file into illustrator and cut out around it and do a photo engrave of this dog (Rowan who had to be put to sleep this year) and all of my photo engraves are turning out dark with no real photo texture.

I have attached a zip file of all of the files I am working with and below are the settings I have on the glowforge currently but have tried others.

Speed: 500
Power: 21
Grayscale: Vary Power
LPI: 450
Passes: 1
FH: .13

This is all on 1/8 Baltic Birch (non proof grade), I have tried with and without masking as well.

I feel like I have read so many photo engrave threads and have tried things people have recommended and keep getting the same/similar results.

Any help/recommendations would be greatly appreciated at this point.

https://www.dropbox.com/s/ac9uaovuhdprq99/Rowan.zip?dl=0

#2

Sorry about Rowan.

As for the engrave I looked at your “edit” jpeg. It’s a great deal darker than you want.

Use photoshop to edit the photo further reply pumping the contrast.

I am a gimp user but my first thing I’d reach for is the curves interface to stretch the dynamic range on that pic from nearly pure white (and I mean very nearly) to pure black.

You generally don’t want to go pure white, as it leads to weird blown out highlights on your wood. (Also definitely no masking)

Anyway once you step your contrast way up usually I’ll crop a small part of the pic and run a 1”x1” test engrave to be sure I like the result. Once I’m happy with that I run the full job. Make sense?

3 Likes
#3

Thanks for the tips, I will work on that now and give it a spin. Pretty sure I understand what you are getting at.

#4

Yeah the end result photo should look like it has way too much contrast, the idea is that it gives you the best dynamic range for a process that really doesn’t have that much variation. Wood engraves Brown, that’s kind of it… you can get some fine results and subtleties in those browns but it’s a delicate balance. As a result, starting with a very dynamic image is necessary to get the most out of it.

This incidentally is why dithering works better in some cases. You basically trick the eye by synthesizing greyscale through dot density. Most people use the dot algorithms in the Glowforge UI but other (I think notably @kittski?) do their own dithering first and then engrave it with vary power.

On the other end of the spectrum people have had some success with things like traveling salesman scores and with masking and painting, and other techniques… but for me generally I like to use a high contrast image and vary power for photos. I think it’s the finest result.