Colour prints from Blender (n00b with many questions)

Discussion in 'Technologies and Hardware' started by syndaryl, Sep 28, 2010.

  1. syndaryl
    syndaryl New Member
    I am new to the Shapeways experience, but trying to learn. I've managed to upload my first STL model and even fixed all my object thickness and manifold checks! I'm now trying to produce enough concept tests to eat up 25$ ;) Very exciting.

    I'm also going over it again to find out exactly how thick it is in places, thanks to the excellent information on the forum here. 1mm cube, go!

    A bombardment of questions for my newness:

    What format should I export to if I want a colour print (my colours are in .jpg image maps)? How do I package it up after exporting for best use by Shapeways? I'm working with Blender 2.49 but I have a couple of other options I can transfer to and then export from if needed.

    What sort of resolution should the image maps be? Currently they are for CGI rendering, which means 2000x2000 (and up) pixels, and I suspect this is way too big. Should I downsample them, or can the Shapeways software do this?

    If I have a rather fat, roundish, creature, fitting in a 1" cube, is this too small for full colour sandstone? The materials detail says it's good for larger objects, but I'm not really clear on what is "large".

    Is sandstone the only option for colour prints at the moment? Is there a better option for small things in colour?

    Is there a script for Blender to compute the volume of a figure similar to the calculation Shapeways uses? I don't need it exactly the same, just to get a good idea when I'm modeling if I have gone too far or if I'm in the right area.

    Other than varnish or shelac or some other clear coat to protect the final product, is there other finishing needed for the colour sandstone? I'm pretty tolerant of a "natural texture" surface, but a solvent soak or the like may be beyond my resources.

  2. clsn
    clsn Well-Known Member
    Surely you can find other cool stuff to buy to fill up the $25... I always can.

    You need to export to VRML. Blender's export has two VRMLs, which apparently are different formats. There's the one near the top of the menu, VRML 1.0, and one that's an export script farther down, VRML97. You need VRML97. You need to have UV mapping performed on your model and everything mapped right, and zip together your JPG texture with the .wrl file and upload the zip.

    You can also make colors with different "materials" within blender, but that's only good for very simple cases.

    I bet Shapeways can do it, but you might want to just to make things easier. Figure how they're going to be mapped to the actual thing, and recognize that the resolution of the color is probably not much beyond 10 dots per mm.

    You can make smallish sandstone things, but sandstone doesn't do so great for fine detail. Fat and round are good things, but it's hard really to say. It's likely worth giving it a try.

    Just sandstone. And painting it yourself at home.

    Go to and download the Shapeways Tools script. It is a very handy thing.

    Can't help you there; I haven't had much experience or experimentation with coating or finishing sandstone. Keep us apprised of what you learn.
  3. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
  4. syndaryl
    syndaryl New Member
    Oh totally... the temptation is terrible. But I've learned that changing more than one variable at a time just confuses me, so I'm keeping the first set of experiments simple. ;)

    At the moment I'm looking at various scales and materials for Mr Fat-Round to see where his center of balance ends up and how the different materials end up feeling.

    Ah, perfect. That's exactly the sort of info I needed. Any special instructions for how to set up texture paths, or is blender smart enough to export a new copy of the textures in the right place?

    I've already got texture maps, and I'm handier in GIMP than blender for painting. But it's really good to know about.

    Glar, at 25mm tall, 2000x2000 is definitely maximum overkill.

    Worth a shot!

    I've got a couple of mini painters I can bribe when it comes to that. I'm going to have a look at Koolaid dying too I think.

    BINGO! :laughing:

    I'll see what I can see. Worst comes to worst, I'll get the aforementioned minis painters to run some experiments for me and report back the results.
  5. aeron203
    aeron203 New Member
    My two cents on finishing sandstone:

    The prints are already infused for strength, but the texture makes them hard to clean. If the piece might be handled often (or in an environment with children) you might want to add a coating. Some are using 1-part epoxy spray which sounds pretty convenient, but I prefer 2-part epoxy. If you give the model a couple of coats it will have a hard, glossy shell that gives even more strength and provides an appearance and feel similar to injection molded plastic.

    The company that makes the printers sells an epoxy coating for $250 per gallon (!), but you can find various epoxies online for around $125/gal. If you're not looking to make that kind of investment you can find smaller kits at marine stores. I picked up 1/2 gallon of resin and a can of hardener from West System at a local boat shop for about $80. You can buy smaller kits but they are proportionally much more expensive. You may see something cheaper, generically labeled "fiberglass resin"- it's polyester and isn't the same thing at all (Tan colored, smelly, brittle). I don't bother with the special pumps and dishes since the ratio is listed on the can. Get inexpensive "chip" brushes and nitrile gloves at the local hardware store. Mix small batches in wax coated paper cups, and let them cure on wax paper so they don't stick.

    Ideally you'd want a clear, slow curing hardener like this one - - but you probably won't see that in the store.

    Finally, don't do it anywhere you wouldn't want epoxy drips forever present, and wear some old clothes you don't mind destroying.

    That all might sound like a bit much, but the results are great.

  6. GHP
    GHP New Member
    I used some clear nail polish (which I happened to have) on one print. (I've had it around for some years, and it is slightly yellowish in the bottle, but not enough to make a noticeable difference on my print, I think.) It brought out the colors a bit better, and I hope it may help protect them also. I didn't put on enough to make much difference to the texture or strength, however. There are also clear spray coatings which you can buy that promise a non-yellowing coating, e.g. Krylon. You could try asking for recommendations at local art-supply, drafting or hardware stores.

    These are undoubtedly far more expensive in large quantities than the epoxy alternatives, but may be good if you're just doing some experimenting to start.
  7. syndaryl
    syndaryl New Member
    I'm less worried about raw material strength than I am about dirty fingers and general gunge, really. Well, and discouraging the cat from chewing on them.

    For the first few experimental tests I'll probably use a spray or the nailpolish, but if I do a big run I'll try something bought in quantity.

    Nice benefit of nailpolish is that it should take the anti-nailbiting bitter stuff on top, to keep the cat out :D