This is a small pair of feet designed for making footprint impressions in wax - a slightly whimsical seal for envelopes, or with your signature on the letter itself. Because of the inherent symmetry of the design you can use the upper face to align your print. Also, you effectively get two stamps in one - great for making tracks!
The size of this seal is 25 mm long (about an inch) and about 10 mm wide.
How it was made
My daughter provided reference footprints, which I digitised and used as the basis for the design. I also studied many images of footprints in sand, to help get the contours right. The software used for the 3D modeling was shapeJS. I considered several different options for the overall form, but I'm pleased to say that this one surpassed my expectations.
How to use
Sealing wax is widely, and quite cheaply, available online in the form of small sticks, either with or without a wick. It may also be available (albeit perhaps less easily and cheaply) in craft or gift shops in your area. Don't try to use normal candle wax.
Careful preparation is essential : ensure you are a safe distance away from flammable materials and have a flat, steady surface to work on with safe place to set down your hot wax stick. It is also wise not to do this underneath a fire alarm.
If you are using a wicked wax stick, light the wick, then hold it horizontally or tilted slightly downward, a few centimetres above the target. Wax will drip down.
Your objective now is to get the right amount of wax onto the paper. Remember that the foot is longer than it is wide, and distribute the drips accordingly. I think a slightly random spread of drips looks appropriate here, so don't worry if a few fall a little out of place.
After enough wax is on the paper, blow out the wax stick and place it down safely. Don't rush - you actually have a good few seconds - pick up the seal, align it and push it down vertically into position. Hold the seal in place for 10 seconds or so, then lift it back up vertically. The wax will still be hot and semi-liquid, so don't touch it yet - leave it alone for at least a minute.
At the end of the manufacturing process, Shapeways give the part a polish in tumbling media. Some of this polishing material is practically guaranteed to become lodged between the toes. I strongly recommend that you closely scrutinise these areas before use, and clear out the pieces with a pin or similar implement.
Any bits you miss may come out on the first use, so I also suggest making a test print before commiting to the correspondance you have invested effort in. (If a stone does appear in a seal, allow it to cool and set; I found that it may then be carefully removed with a pin, and the seal will look fine.)