Provide halftones directly

Hi support:

I have used the convert to dots option to build a silkscreen

It was OK but I’d like more control over it

How can I provide my own dot pattern? A vector set of points? A high res image of dots on 3D burn mode?


It’d be tedious, but it would probably work.

You might also try any number of halftone raster generators on the web. With a good initial resolution and proper scaling, you can probably get a good result.

Looks interesting.

For silkscreening it’s important that the dots or lines don’t connect significantly or I’ll just end up with confetti.

What engrave setting should I use for raster to get a faithful representation of the pixels in my post halftoned raster image?

It seems to me that for laser silkscreening we have to ‘halftone’ at two separate scales.

  1. the actual holes that pass ink through the screen.
  2. the pattern of ink spots that are formed on the fabric.

Since ink flows, and the laser holes are tiny, we can (and maybe must) arrange that multiple holes deliver a single dot.

I will experiment with monochrome images with halftone already applied, PLUS the dot pattern generator from GFUI, to see how it comes out.

In theory, if you made your scale small enough with vector circles you could do away with the dot pattern.

If you go the raster route, you could “vary power” and do away with the gfui’s dot generator.

This is all highly theoretical. There are threads about this topic that probably have far more practical info.

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I couldn’t tell you the process in Inkscape, but it’s pretty simple in Photoshop. (There is likely a similar procedure available in other image editing software like GIMP.)

Change your image mode to grayscale, then to bitmap. In the bitmap dialog, set your output resolution to the LPI you’ll use on the Glowforge, and select “Halftone screen” for the method. You then set your screen frequency, angle and shape. (I like to use 45° lines to simulate a woodcut.)


Particularly relevant is Rasterbated Images

Jinx! You owe me a Coke.

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The GFUI’s dot generator is useful, but it seems to lack finesse : importing a simple gradient to the GF creates an image with a bunch of dithering artefacts: for example:

It’s possible these artefacts (self moire) are not reproduced in the printed article, I’ll try that later.

Here’s the gradient I sent to the GF. Safari does NOT do a good job at rendering this SVG, so here’s what Affinity thinks it looks like for reference



The “dot generator” is just another term for a dithering algorithm.

I’m pretty sure that Glowforge is still using Floyd-Steinberg.

So, it’s probably not going to be the halftone appearance that you’re looking for, as far as building a silkscreen.


I tried building halftones out of SVG paths using the excellent (crippleware requires registration), but the GF chokes on the large number of circles (10,000), and never gets to load the UI.

render 1 weeded

Not all SVGs are created equally. How many nodes are in each circle? In theory, a circle needs minimum 2 nodes, more likely 4. If you’re getting your svg back and its overdefined (20-30 nodes per circle), it’d choke the ui pretty badly. You might try simplifying the paths and see if that helps.

Using the Inkscape method I linked to will give you finer control over the number of nodes.

1 node per circle:

<circle cx=“0” cy=“0” r=“12.4” transform=“translate(3339.7 2644.3)” style=“fill: rgb(0, 0, 0);”></circle>

that’s as simple as it can be.

There are 10,000 of them. I have tried splitting this data up, down to around 2,000 per file, but it still fails.

I know there’s been some discussion about maximum node counts, and what exactly bogs own the UI. Searching the forum might find some relevant details. How many nodes total in your file?

See above, I edited my messages to include node counts.

I’ve gotten files with 20k modes to go by splitting up to 4k node-ish chunks. YMMV, and for all we know GF changed their software in the cloud since then, so I don’t know if it would work again.

If you still have one of those files, can you try again. It’s possible GF hates <circle> nodes.

Easy experiment to do, but I’m guessing that’s the problem.

Add a rectangle around the whole thing. Glowforge Support has said this will greatly improve GFUI performance with lots of nodes. Make it a different color (stroke only) so you can ignore the cut.