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This process started as the ultimate way to carve a jack-o-lantern, but other materials can be used to great artistic effect. Carved in bas-relief, the design is only revealed once the material is back-lit.

Step 1: Materials List

What you will need:

1. A pumpkin, or some slightly translucent material.
2. carving tools (if all you've got is a knife, it's going to be hard).
3. light.
4. an image or an idea.

Optional (but recommended)

1. something to project with.
2. markers to transfer your design.
3. a basic graphics program of some kind.

Step 2: Image Selection and Modification

I fielded a lot of questions about image selection at the Makers Faire, and what follows is the best advice I've been able to come up with.

  • use images that have strong directional lighting. You may have more than one source of directional lighting, but very diffuse light is not good. Stronger gradients are better. Camera-mounted flash-photography is bad. Don't pick a simple silhouette, or something front lit. it should be off-angle lighting to emphasize the cognitive dissonance.
  • an image that needs very fine detail for its impact makes the carving very tedious - so avoid extreme subtlety in expression if you're doing portraiture. Pick something that will have punch, even if it is very blurry.
  • I think it's also good to have an image where both the foreground and background of the image have gradients. If the background is always much brighter or darker than the foreground, then your topography won't be interesting. You'll have a plateau or a simple recess that outlines your figure rather than an dynamic interplay of sculptural shapes. (You can fix this in an image you like by messing around in your image editor.)
  • extreme close-ups for portraiture can create interesting and unintuitive topographies where the image jumps out suddenly.
  • at a crazy advanced math level, you'll probably start to be able to see the topographical forms that the sculpture will take based on the light patterns. At this point, you'll want to pick cool-looking topographies that create unintuitive images when viewed from the viewing angle. I wish I could do this better. It really taxes my brain, but it's what I'm trying to get better at.

So, with all that in mind, get your image. Draw something, take a photo, or find something. If you're drawing a blank, google image search can help. pick an adjective and do an image search. Use CoolIris to scan your seach quickly for something that catches your eye.

Now that you have your image, adjust it so that it's easy to interpret into your sculptural topography.
Photoshop, the Gimp, or another graphics program can help quickly reduce the image to something carve-able. You'll want a black and white image with a lot of contrast. Some areas should be washed out (entirely white) other areas should be lost in shadow (totally black) you also want some mid-tones. Use "levels" or "curves" to alter the contrast on your image. Then use "cutout," or "posterize," filters to alter the image. This will create discrete lines from the gradients to guide your carving. You can think of them as topographical isobars. Your goal is to make obvious the light/dark gradients in your image so that you can translate them to height/depth gradients in your carving.

note: if you're carving in something other than a pumpkin, (specifically, something like styrofoam) where you don't want to completely cut through the object, and where you don't have a top "skin" that will create dramatically contrasty blacks, you probably don't want to have an image that is too contrasty. You still want a lot of range, but you want smooth gradients that keep detail in the highlights and dark areas. This is because a solid black area will become an flat-topped plateau in your carving that isn't sculpturally as interesting as a rounded hill or a jagged peak. Take a look at what I'm talking about in the maker's faire styrofoam carving below. It still looks like a block of styrofoam because the shadows got cut off. It would look better if it had rounded peaks rather than a chopped plateau.

Step 3: Carve It.

Before you transfer to pumpkin, make sure that no black or gray area is completely surrounded by white. That would destroy the structural integrity needed to keep your shadows where they need to be. Darken white areas that surround shadows to fix this problem.

Transfer the lines to your pumpkin. I used this tracing projector that I got at a garage sale, but an LCD projector, or an overhead projector would also work. Tracing or transfer paper will work fine if your surface is relatively flat, but I think the effect is much better (and more fun) if you project onto a surface that's not flat. That makes off-angle viewing distort, and the only angle that the image can be viewed from will be in the direction you projected from (also note that your carving should all be done with that angle in mind).

Every area that is white in your image gets cut out completely first. Then you start removing material from areas that are gray. Be careful to leave every black area intact. While you're carving it's very helpful to have a light source behind the carving. A low-wattage light-bulb on a cord is helpful. A good reference copy of the image you're using is also very helpful, because there's almost a cognitive dissonance with this kind of carving. For me the physical shapes and lines carved don't intuitively relate to the final image. it's very helpful to be able to walk away from the pumpkin and see it from a distance while you're carving. I also squint a lot when I do it.

At some point, you'll get to a stage where your image on the pumpkin is starting to look good, and you'll probably find that at different points in the carving process, you've departed somewhat from a linear translation of the original image. My advice: embrace this. Don't try to make the pumpkin look exactly like the image you projected. Adjust lines, think about viewing impact and viewing direction. Make dramatic cutouts, feather your mid-tones in ways that make sense for the pumpkin image. Your original image was a guide to get you started, not something to use to rate your success. Throw it away when you reach 75% completion.

Step 4: Maker Faire Update

At the first Maker Faire I had the opportunity to explain what this is over and over again, and to make some new versions. check

http://www.stripmindmedia.net/blog/2006/05/pics-and-thoughts-from-maker-faire.html

for that update. It has some examples of non-pumpkin carving using this technique, as well as thoughts on the sources of cognitive dissonance that is created in the mind of the viewer.

also this flickr set, if you care to:

http://www.flickr.com/photos/16756594@N00/sets/72157594147643463/

Step 5: Halloween 2007 Update

I carved another pumpkin in 2007

(below excerpted from: http://www.stripmindmedia.net/blog/2007/11/halloween-07.html )

I kinda felt like this was a practice pumpkin in a lot of ways. What would it be like going for a more minimalist twist?

Answer: I think the level of detail and the complication of the forms on earlier attempts actually resulted in a more effective experience.

Drawings of cubes may be classic optical illusions, but I feel that in this case, the viewer's ability to interpret a "normal" cube in multiple formulations (convex, concave, open, closed) in some way over-rides the sense of distorted space. There are other problems, too.

Ask yourself, is the top of this cube open? or reflective? To my eye, it could be either. This ambiguity somehow makes the form less interesting. In the end, this carving does not make you reassess what the source of the lighting is. While it's possible that the top of the cube is a solid reflective surface, the prior knowledge that the pumpkin is lit from within actually pushes you to interpret that the top of the cube is open, even though this means that there's a missing line. It ends up looking almost like a paper bag with a candle in the bottom of it. And that's not such a leap to make from a pumpkin with a candle in the bottom of it.



Hope you enjoyed! now go make something cool, and let me know about it.

-aaron
I should have paid attention when it said get carving tools! The knife was difficult!!! But you inspired me to make this guy :D Except he promptly started molding the next day it was fun to make!
nice! i'm honored to have been your inspiration. thanks for sharing!<br><br>
what other material can this be done in? im more interested in doing it in a material that wont rot like a pumpkin, something more durable for an art project
well, I've tried watermelon, pumpkin, rigid styrofoam (for plant arranging), ethafoam (an open-foam made of polyethylene - often used in packaging materials - it's not rigid), and the kind of rigid foam that's made from expanded polystyrene beads. I don't recommend the watermelon or the expanded polystyrene beads. They're both somewhat translucent, but the expanded polystyrene beads are annoying to sculpt, and a bit too opaque, and the watermelon is a bit too translucent, and the rind does not have an even translucence. The other two foams work well. you can see the styrofoam in the "babyface" picture in the instructable. I haven't tried the craft pumpkins made out of foam, but I will some day.
Thank you so much, what an amazing Instructable. I made an Obama pumpkin!
nice!
OBAMA!
Dude, thank you so much for this! I wanted to do a really cool pumpkin this year but I had no idea how people got the different levels of shading on their gourds. Your instructions were simple and thorough and the part on how to make a template in GIMP was great. I'll shoot you a pic once I get it done. <sup>_</sup><br/>
you have to much time on your hands, that is cool. you need to enter in some contests or something...
It does take a couple hours to carve one of these things. but who doesn't have a couple hours for halloween goodness?
Amazing
i want to make a santa pumpkin
sick pumpkin
It kind of looks like Mr. 47 from Hitman with his ears sticking out.
That's who I thought it was - (Mr. 47 from Hitman) LOL Very nice carving and tutor! If you guys would like to create a shaded pumpkin - I have over 600 shaded patterns on my site. And a How to on the entire process, No Projector needed. (I use transfer paper). St0ney stoneykins.com
Thanks! nice site! so many stencils! I like the projector method because then you get a 2D image that is transformed to the 3D curvature of the pumpkin, however curvy it is. For transfers, it's better if you have a large pumpkin with a fairly flat side, no? I actually like to use an image that takes up most of the pumpkin, so if I used a transfer, it would be pretty distorted. I also like the way the 3D projection creates an image that can't be interpreted from other angles. It creates a nice little surprise when you can finally see it.
What is your website for the patterns to use for carving pumpkins> Thanks - Linda
Anyway it looks awesome.
thanks- i did another one this year, (with vide) you can see it at:<br/><br/><a rel="nofollow" href="http://www.stripmindmedia.net/blog/2007/11/halloween-07.html">http://www.stripmindmedia.net/blog/2007/11/halloween-07.html</a><br/>
I think the end product looks like the bad scientist from half life 2 idk his name, maybe some one can help me out
AHA! that's ecactly what i thought!!! (the G man btw)
lol G man thanks
I think it looks like Voldemort from Harry Potter And The Goblet Of Fire, in a halucenation where he is wearing a business suit.
You just ruined my life. I always thought my pumpkins were good, until I saw this.
thanks guys. I updated it some this morning, because, well, this is the season, right? -aaron.
<em><strong>AWESOME</strong></em><br/>
with a black marker and a piece of plastic this works well with a flash light too. thats what I use when I want to use a custom image that isnt free hand.
this is amazing.
Aaron,<br/>very cool stuff. I've been experimenting on pumpkins for years. I'm no artist, just an amateur who loves to explore this stuff. You can check it out at <a rel="nofollow" href="http://www.tagyerit.com/pumpkin.htm">http://www.tagyerit.com/pumpkin.htm</a><br/><br/>But if you want to really blow your mind do a search for &quot;lithopane&quot; in Google images.<br/>

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