Bouncing ideas for full colour 3D printer

I have been bouncing ideas around for a full colour 3d printer. The design is based off of the recent patent expiring for 3d printers. The concept is as follows, and is purely ideas atm.

- Corn starch, when mixed with an oil or protein will form a hard plastic. A protein I am suggesting is Pectin, but I am open to other easy to acquire protein. Corn starch does not have health hazards and is easier to clean up compared to plaster or plastic powder. Flour was also considered, but debatable its bonding strength. It does have a risk of dust explosion.
- An inject printer head is used to spray out the protein. Pectin has the advantage of being acidic, allowing it to be sprayed. Five colours (black, red, yellow, blue, clear) are sprayed out. Colours are food colouring, but this aspect requires refinement.
- The printer spreads a layer of corn starch then sprays ink onto the surface. The bed is lowered and another layer of corn starch is spread and sprayed on.
- When complete, the user reaches into the powder and pulls out the (coloured) model. The sample is dusted then soaked in an epoxy to harden.

I am putting the idea up here just to see ideas bouncing off on this. I am currently modifying an old inkjet printer and building up some designs on my RepRap. I am hoping to start a alpha design (no colour) in a month or two if things go well.

Sounds cool.

If you don't know about these resources yet, they may be useful to you:

Pwdr Model 0.1
Dragonator 3DP printer
Powder Printing and SLS subforum
DIY inkjet printer

Matt Moses,

Thanks for the notes. I am looking into them. In a side note, I did an experiment. I followed these instructions
[www.instructables.com]

And I was absolutely amazed at what happened. The instructions are simple: Mix 1 tbs corn starch, 1.5 tbs water, 3 drops oil, mix, 30 seconds in the microwave.

The stuff going into the microwave is milky water, what I expected. Out of the microwave is jelly, like mucus if you want. It is clear with bubbles in it. Wait for it to cool, then plop it down on something. It will harden in a few days into a hard, clear plastic-like material. Very hard and takes food coloring.

I doubt this material will work. What it does is convert the watery slurry into jelly with the addition of heat. I had hypothesized that dripping water on to corn starch would have produced a ceramic-like material.

Man, things you learn. Try this. It is a cool, easy, cheap, <5 min experiment

I think you made PLA.