I've been experimenting with metallic paints on 3d printed objects and spray on patinas. Photos and then a description of technique and products below.
- Sand surfaces with 220 grit if smooth. Surface that are too smooth will be hard, though not impossible, to paint thinly.
- Brush a layer on as thinly as possibly. The print surface will show through. It will dry fairly quickly. If you can see brush strokes while the paint is wet, that is too thick (unless you like that look). Once dry, if you want to get rid of a brush stroke or drip you'll have to sand it down.
- Once dry, apply another layer. The deposited metal particles will roughen the surface so that subsequent layers of paint adhere better and get more coverage.
- The brass paint got brighter as it dried. It sometimes had a dull look when wet but that goes away.
- The patinas must be applied when the paint is wet to stand a chance of interacting with the metal particles, so apply a final thin wet coat and patina immediately. If too thick, the paint has a tendency to crumble up (cottage cheese is another description I've heard). Some patinas will also just deposit some color on the surface and so would be at least partially effective even on a dry coat of paint.
The patinas I used were the following products from Sculpt Nouveau:
- Tiffany Green
- Jade Green
- Deep Brown
- Vista Rust (Bender head only)
I mixed and matched the for different effects on the different objects above. The Jade Green leaves obvious green deposits immediately on the surface.