Introduction: Complete Stencil Tutorial Using a Free Program
A tutorial on making a stencil with an open source program called the GIMP.
I looked on all the Instructs tagged with stencil, and not one gives a step by step for making a stencil in my favorite open source photo program The GIMP.
Step 1: Materials and GIMP
-What You Need-
-printer
-craft knife
-The GIMP
-surface to cut on (self healing mat)
-spray mount (optional)
-spray paint
GIMP is an open source raster based graphics editor. It was designed to replace Photoshop.
You can get it here. gimp.org
Install it, open it up, and familarize yourself with the interface for a bit. Done? Good. Isn't open source great? Didn't cost a dime!
Step 2: Pick an Image and Open Your Picture in GIMP
Pick a good simple image (remember: simple equals less cuts) preferably on a white background. This can be hacked by simply erasing around an image in MSPaint or what have you.
I chose a tasteful Stormtrooper sculpture to stencil. Nerdtastic!
Step 3: Crop It
Crop out the parts you want to make a stencil of with the Crop/Resize Tool (Tools>Transform Tools>Crop).
a. GIMP allows you to save a copy in case you want to use the uncropped-unedited image later. Save the copy, then go open the copy in GIMP. (File>Save A Copy)
Step 4: Simplifying the Image
We need to simplify the image now. We will do this by Colorify-ing the image. There are two ways of doing this in GIMP.
a.One way is to go to (Tools>Color Tools>Colorize). If you use this method, you will want to set the Hue and Saturation to 0, and adjust the lightness to fit the image (this can be done to taste, generally you want about an even light to dark for a stencil.)
b. The other (and redundant) method is to go to Filters>Colors>Colorify, and select your color (you'll be selecting white).
Both methods are pictured, I chose to use the filter.
Step 5: Tweaking the Contrast and Brightness
Now I'm going to tweak the contrast and brightness a bit. (Tools>Color Tools>Brightness-Contrast) I'm trying to get a hard line on the helmet, the hardest part on this image to keep intact.
Step 6: The Threshold Tool
Next I use the Threshold tool (Tools>Color Tools>Threshold) You'll want to play with the settings to get good hard black and white , which is perfect for stenciling.
Step 7: Stencilable Image
There you go! You end up with a semi usable image.
The key to stenciling is to editing out the "islands" of white in your image. You can make little bridges for them if need be. Once again this can be accomplshed in whatever bitmap editing program (MSPaint) you have lying around. I think the image I have can be edited by hand, so I'm going to print it now.
Step 8: Get Ready to Cut
Get your craft knife(s) and you image and get it all ready for slicing and dicing.
Step 9: Outline Your Cuts (optional)
If you have a fairly low res image, this is a good idea. Silver sharpie.
Step 10: Cut and Spray
Once your done cutting, it's time to spray. A simple one layer will do (you could make a 1.5 layer but that's a different tutorial)
As for spraying.
A guide to cutting stencils
• Think from outside the box.
• Collapse the box and take a fucking sharp knife to it.
• Leave the house before you find something worth staying in for.
• It's easier to get forgiveness than permission.
• Spray the paint sparingly onto the stencil from a distance of 8 inches.
• Be aware that going on a major mission totally drunk out of your head will result in some truly spectacular artwork and at least one night in the cells.
-Banksy
Have fun!

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117 Comments
7 years ago
thx for the good work!
i've done the same but my pict was more bigger :)
Besides, I've printed my stencil by poster printer on my a4 printer.
Now, at my home really "star wars"- atmosphere :)
8 years ago on Introduction
8 years ago
Great job on this instructable and you get extra points for making me laugh!
15 years ago on Step 10
hello great job... this isn't Really about this instructable but though you could help... I currently have a screen printing business and I'm trying to make a 3 - 6 color shirt.. is there a way to separate each and every color? (using gimp, word, or publisher?) the response would be greatly appreciated...
Reply 8 years ago on Introduction
For automatic color separation (2-5 colors) and auto-bridging the stencil, try out
http://baystencil.com
It turns any image into a color-separated stencil with bridged islands.
Reply 14 years ago on Step 10
It's really easy to do just go image>mode>indexed, select the amount of colors (white backround will count as color) you want and click convert.
Reply 15 years ago on Introduction
yeah, you can select each color and separate each one as it's own layer.
12 years ago on Step 10
hi i have a question about the spray painting itself,
i made a stencil a while ago and i wanted to test it before spraying it to my old guitar. but this is what happened: after testing the stencil, the paint caused the paper to curl up.
do you have any idea how i can prevent this the next time i do this?
greets,
Jelle
ps.
my English may be not very good because i am from the Netherlands and i am 14 years old.
Reply 8 years ago on Introduction
You can spraymount (3M spraymount) the printed page to a piece of cardstock, then when you cut it out you have a more durable layer that will stand up to several sprayings. Make sure to lay the stencil flat while it dries. Another option is to use Grafix stencil sheets. 5mil or 7mil works best.
8 years ago on Introduction
You can stencilize any image without Gimp or Corel Draw, using http://baystencil.com
For example, the stormtrooper here:
http://www.baystencil.com/stencils/order/7c8c05836...
You can totally cut it out yourself after printing the bridged, decomposed images from the website.
9 years ago on Step 8
What if I want more layers?
9 years ago on Introduction
this was very comprehensive, thank you for making this you are a swell individual.
12 years ago on Introduction
how did you blow up the image?
12 years ago on Step 7
Threshold doesn't work :/ My image comes out pixelated
12 years ago on Step 10
My God man!! This is a giant help and I think I love you... just sayin'... and thank you so much for using GIMP. I fell in love with it like 2 years ago but I never knew I could make a stencil with it. That was stupid easy.
Reply 12 years ago on Step 10
No problem. :)
12 years ago on Introduction
Nicely done. i will check out the GIMP. Can it do something that a high-levcel Photoshop program cant? cuz i have one and it works fine.
12 years ago on Introduction
Thanks a LOT for this i'ble man!
15 years ago on Introduction
Here's Mine: Just can figure out how to print it.
Reply 13 years ago on Introduction
Nice. The other side of the helmet (if this is the one from Full Metal Jacket) would have made for a nice ironic stencil, too.