Optimal dpi in PDF?

I won’t receive my Glowforge for probably another month, but that doesn’t mean I can’t start creating designs for what I would like to make. I’ll be working in Photoshop and printing from PDF files. Is there an optimal dpi to work in? Is 600dpi too fine? Not fine enough? Is there a minimum number of dpi for cutting? I read in a section on etching PCBs that 1.5pt is the finest that can be cut, is that the case regardless of the file’s dpi?

Welcome to the fun!

Even though Photoshop can save out PDF files you won’t be able to cut from them because Photoshop is a RASTER program. The DPI/resolution will only matter for engraves. To cut or score you’ll need to create VECTOR artwork in a program like Illustrator or Inkscape. (vector files are resolution independent, PDF is a container format that can contain both raster and vector elements)

As for fineness of cut, that all comes down to kerf (width of material removed by laser) for a particular material and the speed/power settings you’re using on that material. Typical kerf on 1/8" woods hovers around .004" for me.

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DPI = LPI * 2
LPI = DPI / 2
So it would make sense to raster at 2x the planned LPI. I try to do this if I am planning on engraving photographic elements. For solid graphics I would stay at my default of 300 dpi if I were to rasterize them.

Now, that only applies to raster art, which will be for engraving.
For cutting you need vector lines. vector lines don’t care what DPI you select for output to PDF.

Photoshop has some limited vector capability. I wrote a thing about it a while back:

If you have access to illustrator, I would highly suggest playing around with it while you wait for your GF to arrive. If you don’t have access to Illustrator, go check out Inkscape (free).
You will get so much more out of your GF if you have a vector-editor as part of your toolkit.


Thanks for the answers and the Photoshop vector tutorial! Here are a few more resources to help you get started, @OldFrog.

You can always access the most recent version of the Glowforge manual at https://glowforge.com/manual or in the Support area of the App, where you can also find Learn by Doing tutorials as well as Troubleshooting for the most common problems.

Our Glowforge Community has created a wealth of tutorials to get you started using your Glowforge right away, like the one @jbv posted. You can find these in the Tips & Tricks section of the community forum.

The Learn by Doing series has a couple of intros to Inkscape:

You may also find Working With Manual Mode (also part of Learn by Doing) useful, especially the section “Engrave Resolution,” which addresses LPI.

I’m going to close this thread. If you have further questions, please post a new topic.