Silkscreen from card stock

[jcberry]

This was a fun project. I wrote a script to convert a .jpg photo into an array of halftone dots and output an .svg file of the pattern for the Glowforge to ingest. It took a few hours to cut all 29,192 little holes in the sheet of 25mil black card stock paper.

The image really shows well with the card against an overcast sky, or with a point-light projecting the image onto a wall. It’s also a handy mask for spray-paint, as I made this image by laying the screen on a sheet of fabric and spraying it with UV-fluorescent ink. I’m happy with how truly nonvisible the ink is, until intentionally illuminated with a UV inspection lamp. The ink is “opticz” brand, found on amazon. I used a kitchen spray bottle to mist over the paper/fabric stack.

[evansd2]

Excellent!

Hours you say? I wonder if a high power engrave would have been faster?

[ptodd]

Nice project! It’s fun to see the Glowforge used for so many different types of projects.

[jcberry]

That’s a really good question! I hadn’t considered that. --more smoke, for sure!

[markevans36301]

This is kind of genius in that there is nothing new here just a unique way to combine things I already knew about in a new way.

[evansd2]

The script aspect is cool.

If anyone wants to give this sort of thing a try inkscape can make vector halftones. I wrote it up back in 2017:

Halftones in inkscape

Short version: There’s a way to make halftone images in Inkscape. [image][image] Long version: I remembered this technique from a few years ago when I was playing with a pen plotter (No, not a polargraph, but I still kind of want one). Basically, you use Inkscape’s tiled clones feature to get the result you want. This allows for crazy control, but one warning: Be careful of how many nodes you have in your “dot”. It scales up incredibly quickly, and pretty soon you’ll have a beast of an SV…

[hansepe]

I’ve been using this for years to accomplish the same thing.

Wall art generator - Rasterbator

They do look cool once you make them!

User tip: I always use the largest picture I can, put it in a PDF and then scale back to the size I want.

[evansd2]

Yeah there was this post too where I rounded up a few posts on the topic:

Area of Effect Game Templates

Stipplegen and the rasterbator and halftones in general have been covered elsewhere: … and more. Search around, it’s a pretty well-discussed idea.

[rbtdanforth]

Even at 1355 LPI I dont think the image would be as good or much faster. The fastest speed to make each spot would be very reduced also. I don’t remember when they fixed the accelleration issue but it definitely would not have worked before that. Even if you increased the cutting speed it would go to the lower speed and cut down on the power that the fix does.

It is a beautiful idea for projecting stuff along the side of a building!