What's the best way to make sharp, detailed, flexible custom stencils?

April 19, 2008 10:14 AM

What's the best way to make sharp, detailed, flexible custom stencils?

I want to make some stencils for a couple of projects. They should be flexible enough for wrapping around a bike frame for spray painting (paper would be fine) and strong enough to hold up under sandblasting. (I've found that a couple of layers of masking tape can handle it.)

A laser cutter would be ideal, but it's out of my range. Am I stuck with cutting them out with an X-acto knife? I'm not so good at getting the curves and details I want.

posted by hydrophonic to sports, hobbies, & recreation (8 comments total)

I have hand-cut many a stencil for painting. I've never tried to sand-blast, but a thick mylar should work. It's at least as thick as a couple layers of tape. You can find thick but flexible mylar film which should wrap around a bike frame and hold in place with tape. You might also use some spray adhesive on the stencil to hold down the edges, although I have never tried it.

As far as cutting: An exacto knife is my preferred method, and it's not too hard with some practice. It's hard to describe, but anchoring your pinkie by pressing it to the table as you cut gives you a lot of control. You can also get an electric cutter that uses heat to cut the stencil. It's basically a cheap soldering gun with a very sharp replaceable tip. I don't care for that as much because the cut edge tends to be a bit rounded, instead of sharp and flat. This may not matter for sandblasting.
posted by Fuzzy Skinner at 10:33 AM on April 19

I'm slightly obsessed with Plaid Simply Stencils uncut blanks. Unlike paper the little fiddly detailed bits don't get bent or ruined, they cut smoothly under reasonable pressure, and the material is sturdy enough that it can be used over and over.

I, personally, like to pair them with a self-healing cutting mat, X-acto Gripster, and a few coats of spray adhesive all over the back once they're ready for positioning.
posted by Juliet Banana at 10:37 AM on April 19 [1 favorite]

Frisket is a plastic film used for making airbrush or silkscreen stencils. It consists of two layers of translucent plastic that you can lay over a drawing. You cut out the top layer, which has an adhesive back; the bottom layer does not cut easily, so provides a cutting surface and protects your drawing. Then you peel off the top layer and stick it to your bike, or whatever you're painting.
posted by weapons-grade pandemonium at 10:49 AM on April 19

I use Avery 11900 plastic 3-ring-binder dividers for stencils. They're cheap, strong but flexible, and easy to cut with an x-acto knife. But I'm too impatient to do all the cutting myself so I got a craft robo - it's basically a laser cutter, only with a knife instead of a laser; cuts directly from Adobe Illustrator or its own software. $300 or so. I've made some pretty intricate stencils with the plastic sheets and craftrobo.
posted by moonmilk at 11:36 AM on April 19

Take your design to any sign shop and ask them to cut it out of the cheapest (if you wanna speak the lingo call it a "3-year" or "3mil") vinyl they have, and mount it on application tape.

It will take them all of 2 minutes to cut and mount it... and they'll probably charge you the shop minimum ($25 or so) for the job you describe. (or around $10/sq foot if you wanna run larger orders).

You'll end up with a precision-cut stencil "sticker" made out of... bumper-sticker-style material.

Apply to your bike frame, paint, wait to dry, remove. Way easier and more accurate than futzing with X-acto knives... (of course, I love futzing with x-acto knives, but I realize that I'm in the minority).
posted by cadastral at 12:21 PM on April 19

(not to mention that you're going to have a pretty HORRIBLE 'underspray' problem unless you can find some way to bind your stencil material TIGHTLY and seamlessly to your substrate. Not as easy to do with mylar/overhead transparencies/rubylith/stop-etch/whatever as you would think. [Did I say "not as easy"? Change that to "more-or-less impossible" without a LOT of experience doing it...] ).

[8 yr+ stenciler/sign-maker]
posted by cadastral at 12:28 PM on April 19

Just to make it clear... the downside to the method I suggested is that the stencils produced would be in no way whatsoever "reusable". If this is a one-off project, this will be no big deal... but if you are painting 100 bike frames, it may be.

But... come to think of it, I still think it would be economically viable (and justified by the superior quality of your final product) to cut 100 vinyl stickers. Back-of-the-envelope, order-of-magnitude estimate, here: Say 1.5" diameter bike-frame, that'd be around 4.75" of vinyl (liberally) per stencil. Roughly 3 stencils per running foot... eh, it's not as cheap as I thought.

BUT... it'll look nicer, and you might save it in labor, in the long run. The stencils made out of the various non-adhesive mediums listed above will have to be replaced every 3-5 applications, as well.

Good luck with it... I really think sign-shop/vinyl sticker is the best way to go, when ease-of-application and quality of finished product are considered. Email me if you'd like more guidance with how to talk to the sign shop folks, if you decide to go this direction.
posted by cadastral at 1:22 PM on April 19

I use 3mil mylar, which I wash and reuse. However, I'm using water-based fabric paint, always on flat surfaces. Not sure how it would hold up wrapped around metal like a bike. There is also heavier mylar. The sandblasting idea sounds very cool; not sure mylar would hold up to it, but there you have it. I have stencils I've used repeatedly for more than 20 years, some with very intricate designs.
posted by nax at 3:29 PM on April 19