The Médaille Coloniale -- the French Colonial Medal -- is a prime uniform decoration for any good 19th-century soldier. Adding some campaign clasps to a recreationist friend's medal seemed like an excellent project to test out the Shapeways workflow, from reference images to final prop.
This instructable is mostly concerned with the method(s) of working in scale from photograph to final item.
Step 1: Collecting and collating reference material
My friend had already done this step for me; he determined the campaigns his character would have served in, and found appropriate images online for each of those clasps. Although the medal itself is official, campaign clasps would be run off by whatever jeweler the soldier had access to -- thus the font and border details varied widely.
Fortunately for us, however, they all hewed to a regulation size; 40 mm x 10 mm. These round numbers made working to scale much easier.