Flexible / Resilient material recommendations?

Hi folks – this is my first post, so hopefully I’m putting it in the right place. I’ve had my GF for about a month now and it’s really accelerating my projects in a fun way. I do a lot of design for retail and packaging, and one thing I’ve been trying to figure out is a clip system to connect pieces of cardboard. Think of it as a fancy version of an old wooden clothespin – not the springy kind, the kind that’s just a dowel with a slot . I cut a bunch of prototypes out of draft board and acrylic and the form works great but they all just snap under pressure. Can anyone suggest a material that would have more flex to it but still be able to cut by laser? Even if I had to send out to have it cut, at least I could prototype at home first. I’m worried I might have to 3D print or injection mold this to make it work.

Oh and I started out using actual clothespins but they generally wear out (the springy ones) and the dowel ones aren’t the right size for the materials I’m using. And none of them look good.

Any advice is really appreciated - thanks!



I am not sure about flexible, but I have been told that derlin is a type of plastic that is strong and can be lasered. I recommend giving Inventables a call and ask about settings and flexibility. They have been very informative when I have called.



Good advice^^ if you were to explain to them your application as you did here, I’ll bet they could recommend a material. I agree with Delrin.


I’m kind of surprised that the plywood ones keep snapping (very cool clips by the way). Maybe tweak the sides a bit? I agree with Delrin as a possibility, although that stuff is so slippery you might find the clips popping off. I wonder if you could treat some other material (leather? Cardboard?) with something to make it strong but flexible. Some kind of acrylic sealer or resin, maybe.


Thanks! I know some Inventables people but haven’t spoken to them in ages, that’s a great suggestion and delrin in particular feels promising. Appreciate the recommendations!

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I don’t think the OP said plywood was snapping. The post mentions draftboard and acrylic, but not ply.

OP: correct me if I’m wrong about you trying ply already. If not, I don’t know if ply would have enough flex, but I would try cutting one and see. Other then that, as others have said give inventibles a call and wait for more people to chime in here.

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Oops, you’re right! I would also recommend trying the ply.

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You may want to look at nylon. It is highly resilient and won’t break.

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I have some ply but haven’t tried it yet – mostly because the proof grade ply isn’t very thick, I pretty much assumed it wouldn’t hold up to use. But it would be a good test and certainly would look nicer than anything else if it worked. will definitely try that.

Have you considered changing the spring design in them? Instead of having it going back and forth from inside to outside, maybe have two cut outs that go up through the crown of the design like this.


(Sorry started mocking up a design and got out of hand :rofl:)

I guess I’m assuming that they’re breaking at the points where you’ve added the spring section, is that right? Also is there a particular reason they’re at the thickness that they are? Adding a bit more meat to them would also help, like in my image, but it wouldn’t lay particularly flat with the rounded top.


I do a lot with Delrin and it has some flex, but will break past a point.

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hey I’m impressed you actually knocked out a prototype – that’s a smart idea for locating another flex joint! I tried some thicker ones but they had no spring at all. I’m also looking at 3D printing these out of nylon – seems like that might be the toughest small-batch solution.