Thank you for your in depth response. I'll clarify:
As far as materials, I'd like to be able to print (please excuse my lack proper terminology) hard plastics and flexible plastics (rubber?) in colors that range from completely transparent to completely opaque.
[In the same part? The Form1+ is a relatively inexpensive SLA printer that can print with clear and opaque resins. But you need to choose one or the other for each part. The Objet printers from Stratasys are probably your best bet if you need a gradation from transparent to opaque in a single part. But these are not cheap at all, as Richard points out. ]
Also it is very important that it can print with materials that are safe to consume food or liquids out of (not every item will need this property though).
[That lets out most 3D printing materials, with the possible exception of PLA, which isn't particularly stable.]
It would be a huge plus, but not necessary, if it could print materials that are metallic or metal, glass or glass-like, or biodegradable.
[There are printers that can print in metals, but so far they cost hundred$ of thou$and$. The atomized metal powders they require aren't cheap either. Glass printers so far are only experimental; I don't know of any on the market. But PLA is supposed to be biodegradable, to some extent, anyway. ]
The ability of paste and food printing would not be of much or any use. A CNC milling machine would be useful, I want to stick to 3D printing for now.
For colors (meant to type multiple not multiply, oops), I need something, like you said, with multiple extruders. I'm looking at a
model from ORD Solutions that has five extruders. I was informed that it could print 15 different kinds of materials and has a very high printing resolution, which is also something I need from the printer. Do you think something like this would be ideal for my needs?
[It's hard to say. That looks like an interesting machine, but how well it really works is questionable - with its 3-month "parts only" warranty it doesn't seem like the manufacturers have much faith in their workmanship or its longevity. They only have one fairly crude example of multi-color printing in the same piece, and while it looks like it can print colors discretely, it's certainly not doing photographic reproductions. Its products don't look like things I'd want to eat or drink from, and washing them effectively would be a problem, since it not only has all that surface for things to get caught in, but if it's PLA, it might start to biodegrade.]
I will look into the software as well. I would assume if this is a possibility, it would be done in the software but, can you print at a crude and quick resolution for the parts of the item that aren't visible, while printing the outermost layer in the slower but highest resolution setting?
[Some printers might support that, but I don't know of any off-hand. It wouldn't be done in the modeling software; the slicing software would have to accommodate that. ]
I know with the model I'm looking at each extruder can have a unique nozzle size, if that would help with this. Essentially I want to print something that looks great but can be printed quickly.
