Mixed Media tools: Foam stamps

This is a tester foam stamp for use with acrylic paints in mixed media artwork. I engraved and cut it out on the Glowforge.


Worked like a charm.

I used EVA foam, which I got in a roll from Michaels (in the cosplay section, not near the fun foam). It came in 6 mm, 8 mm, 10 mm and 12 mm thicknesses. Despite the math, the Glowforge sees the 12 mm as thicker than half an inch, so to avoid the hassle, I went back to the shop and got the 8 mm thickness. It’s still thick enough to grip nicely.

To get it ready for the Glowforge, I cut off a piece of foam, and warmed it up with a heat gun (not a powerful one; this is a little hotter than a hair dryer), and then pressed it between a couple of books while it cooled. It flattened right out.

In the Glowforge, I used these magnets to hold it down.



I covered each of them with tape to make it easier to pick them up .

I experimented with the settings, and ended up with this:


Engrave:
Speed 400
Power 55
75 lines per inch
grayscale: vary power

Cut:
Speed 175
Power 85

I was always a little reluctant to use other people’s stamps in my artwork, so I’m super excited!

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That did a fabulous job!

1 question. Why the heating with the heat gun/flattening? Was it because it was the 12mm and the :glowforge: wasn’t reading it, or did you flatten the 8mm as well?

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Because it comes on a big roll like this.


My magnets weren’t strong enough to flatten it out, so I heated it a little to help it uncurl.

Foam sort of softens with heat. You can make temporary foam stamps by warming up the foam (like with a hair dryer), and then pressing something into it (legos make cool patterns). The foam will keep the impression until you heat it up again.

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Got it! For flattening it makes perfect sense. I was thinking it did the laser cut differently if pre-heated or something :slight_smile:

I love the idea. I’m thinking some superglue and a T of wood into a circle could get you a handle on the back that would still press evenly.

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That could work. I don’t think I need a handle, though. I have a bunch of these https://artfoamies.com and they work pretty well without extra support.

I need to go ahead and design some stamps, now that I have my settings!

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Thanks for sharing your process. Now that you have the production worked out, I look forward to seeing your stamped creations.

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I wonder how the level of detail and accuracy of the stamps will hold up against a more traditional laserable stamp rubber?

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I’m definitely adding this to my stamp repertoire. This method would be ideal for larger stamps—the laser polymer and rubber stamp material is very expensive. Thanks for the inspiration!

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Great idea! Just a caution – try to keep the magnets in front of where the air assist will pass. I had to return a machine after the air assist died – I was using magnets, and it started failing frequently. Eventually it dawned on me that it was failing whenever it passed over a magnet, and I stopped using them, but it died anyway. I still don’t know if it would have died without the magnets eventually, or if they caused it, but now I only use them rarely, and only toward the front.

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This!!!^^^^ I had the same issues! And the same “Back to the Mothership” but fortunately no flames.

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Oh how I love cheap material hacks… Thanks for the walkthrough!

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I got some of the orange rubber from amazon too. They are for different things. When you use acrylic paint on rubber, you have to clean it carefully, or the paint will fill the gaps in the stamp and ruin the image. They really are only practical to use with inks. I really rarely clean my foam stamps, more than wiping them off so they don’t get paint on stuff.

I guess that’s not what you asked though. In my red circled trial #7 that you see above, the carved out circle is 7/8" and the circle within the square is 3/4 inch diameter. The two circles were the same size in the design. I was thinking about using a score line around the design first and then engraving out not quite to the edge of the design, to see if I can get more precision.

Also, I used a blur to make a gradient around the stamp image on my test stamp, so the cuts are not as deep and they seem to have come out more precise. I am not sure that was necessary, but it might have made the design a little finer.

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Yeah I’m sure I don’t need to tell you that EVA shrinks a bit with heat.

Maybe it’s like a kerf setting to keep in mind, I’d imagine the shrinkage is pretty predictable?

I did get an error about the assist fan not running at the right speed, and then, like you did, moved my magnets to the front. I can see how it might stress the assist fan motor if you drive over those powerful things repeatedly. Maybe I should design seatbelts for the foam that doesn’t require magnets… hmm.

I’ve been cutting stencils using magnets too, but the stencil film is not thick, so the magnets are not as close to the fans. I might use weaker magnets for that, since I don’t need the mega scary ones to hold that thin plastic down.

What does “Back to the mothership” cost you other than time? I don’t suppose you could replace that fan yourself if need be?

They did a warranty replacement, thank goodness, so I’m not sure what it would have cost!

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Have you met my new friend?

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Glue a magnet to the handle and the stamp(s) so you can use multiple images.

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I did see that. It’s fab. How sucky is it? would it hold down this thick foam?

I’m worried about the close the chord in the door part, as I’m not up for cutting a hole in my machine at the moment. I have a Plus. You tried it, yes? Does the glowforge think it’s closed?

This would be exceptionally helpful making detailed stencils. The little bits pop out and fuse onto the stencil. I have to more or less scrape and poke them out after. I’d love to skip that step.

Sort of? The laser goes back and forth when engraving, and edges that are more parallel to the engraving direction seem to shrink back a little more than edges orthogonal to the passes. Or at least it is somewhat nonuniform having to do with the direction the laser is passing.

That said, the stamp came out pretty dang circular. These foam stamps are not high precision anyway. You’d want to use a harder material like rubber or wood for block printing if you wanted precision.

I was thinking velcro, but yeah, good idea.

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