Preparing a Photo for Raster Engraving

engrave
tutorial
raster

#1

@Dan has let us know that none of this mess is necessary to engrave photos on the glowforge, so I guess you can take a look at this and be thankful you dont have to go through all this trouble! awesome!


As forum users are starting to get glowforges, I figured I might as well put up this tutorial for everyone to reference when preparing their photos for engraving. This will give a very similar result to what you would get using photograv.

Ill just do one you guys have seen already, since I have the engrave on hand:

Open the file in photoshop.

Top menu: Go to Image -> Image Size.

Change the resolution to the native resolution of the laser you are cutting on. Mine is 300 so Im setting it to that.

Make sure AFTER you change the resolution (DPI) that you set the width or height in the pixel dimensions section back to 100 PERCENT.(photoshop changes this automatically)


ok, now were ready to begin.

click on the image layer and go to
Top menu: Image -> Auto Tone
This should fix most major contrast and/or color issues in non post processed photos.

Next youll want to create a few adjustment layers:

Top menu: Go to Layer -> New Adjustment Layer -> Black & White
Top menu: Go to Layer -> New Adjustment Layer -> Brightness & Contrast
Top menu: Go to Layer -> New Adjustment Layer -> Curves

Set the Brightness & Contrast to 25 each (more if necessary).

It should look like this now:

At this point youll want to save your file as a PSD, because we are going to be doing some destructive processes next.

Once everything is saved select the image layer and go to
Top menu: Filter -> Sharpen -> Unsharp Mask

Use the following settings:

Go back to
Top menu: Filter -> Sharpen -> Unsharp Mask
and use these settings this time:

Your Image should look like this now:

It may look quite a bit messier than before, but trust me, when lasering you need to have strongly defined edges.

Next you will want to go to
Top menu: Layer -> Flatten Image (hit ok when it tells you it will delete the black and white adjustment layer)
Top menu: Image -> Mode -> Bitmap

Use whatever the native resolution of the laser cutter here. (not LPI, but DPI)

It will convert your image to a stippled image and should look like this: (it looks better if you zoom in)

Go to File -> Save As
and save your image as a BMP

I usually also put the image dimensions in mm in the name and what im going to do with it (cut, engrave, etc) in the name. You have to manually put image dimensions in the chinese laser software. Cant wait to not have to deal with that!

Now youre ready to take it and try out the engrave!


Pre-Release | Greyscale Engraving, A Comparison to the K40
#2

For those that are wondering what the curves layer is for, if the engrave doesnt come out how you hoped, youll more than likely have to do some adjustments to lighten or darken certain parts. Curves is great for this. So you might not use it if youre really lucky on your first try, but you will at some point in your engraving adventures. Every material engraves differently, and one file might work on cedar, but wont work on birch or walnut.

It might be worth your while to set up some gradient tests on different woods to get an idea of how they engrave. You can probably even create a photoshop curves preset for each type of material.

Hope this is helpful!


#3

Nice.


#4

Thanks for the refresh! hopefully I’ll be putting that to practice soon :wink:


#5

hey awesome tutorial. definitely bookmarked!


#6

wow! thanks for this great tutorial :smiley: bookmarked :wink:


#7

Awesome tutorial!
(Deliberately saved this one from earlier today so I could study it!) :grinning:

It’s both easier than I thought it would be, and has a lot more steps than I expected. Great effect on the wood!

Thanks for telling us how.


#8

Thank you SO much for doing this! I’m not likely to be doing it a lot so having a step-by-step is incredibly useful!


#9

Can someone show how to do this in inkscape? I don’t have AI, but I really appreciated seeing the steps.


#10

OOL, thank you for sharing.


#11

I havent used inkscape, but from what I know its a vector drawing software, which is more of an analog to illustrator as opposed to photoshop, which is geared more towards raster based images. There is free software out there called gimp, along with a number of others which are raster based image editors, that you might be able to use to follow this tutorial.


#12

Ahh yes, you are right. I downloaded gimp, but haven’t used it yet


#13

You can do it in Corel too. There are a couple of decent videos on YouTube that show the steps.


#14

Nice tutorial. Thanks. And thanks to nick07lee I knew how to bookmark this thread:grin:


#15

Excellent tutorial. I’ve worked with photoshop for years but adapting to the needs of the laser. Great write up.


#16

Will use this for sure. Thanks so much.


#17

This is one of the insta-bookmarks


#18

This is exactly the right thing to do with a conventional laser, but don’t do this with your Glowforge. Give us a greyscale image. (Bumping contrast and sharpening are good ideas). We do tons of smart things with the extra data, and if you try to dither at a fixed DPI, you’ll wind up with results like… well, like a typical laser.


#19

This is one reason I’ve tried not to pay too much attention to what people do with conventional lasers. Between camera magic and cloud magic, I’d have to get rid of a bunch of good habits for conventional lasers that are bad habits for this new one. Vector drawing, though, I will stick to convention from what I have learned so far.


#20

Awesome. Can’t wait to play with this