I have added a step by step and some more detailed info for Zbrush users. This should be all you need to know for Zbrush 4R2
This is what worked for me as a Zbrush artist. These are tips that I learned in the process that I could not find on the site easily. This is geared towards just zbrush users.
1. Remember when you are modeling to hollow out the major part of your model. Ie. If you are doing a head—hollow out the head a bit. If you are doing a full body—hollow out the body. Use the Dyna mesh-Create Shell feature. There are a number of tutorials on this. Remember the less area you take up the less the model will cost. For my model I used a thickness of 4 on the create shell option. I think that is considered thin actually. (depends on how small your model is) You do not have to hollow out every piece just the big ones or you can just pay more and not hollow it out. I would say the price difference is considerable for hollow to non hollow models.
2. Also if you are running out of memory doing this create shell process (which I did) go to preferences – mem and set the compact memory to a gig. Initially zbrush starts out with only 256mb of ram.
3. Be sure to make a base for your model or a stand. Remember that thin poles that are supports can fail in the printing process. This is something that I did not take into consideration when building my model. I just stuck some poles though the model to stand up like a table. Since they were thin (They got thin when I scaled my model down to 24mm high.) of course if my model was 5 inches high like it was on my screen those poles would have been thick enough. Supports should be strong and big.
4. Materials- Kraftwurx offers a bunch of materials. But not all can be “color” printed. Multi-Color Sandstone is probly the best and offers the ability to color at the same time. It’s also one of the cheapest materials as far as price!
5. Zbrush users remember to scale your model before you upload it. Set the scale of your model in the zplugins-3dprint exporter. Set to mm and set your model dimensions.
6. Saving to export- Use the zplugins – 3d export to save as a VRML file. Remember to check EXPCOLORS too. this will add the UV info to your file. Otherwise if you just export an .OBJ file you will have to export and upload a UV map later. Both options will work though. Other options exists I am just focusing on these 2.
7. So you are done and ready to upload First make sure your model is less than a million polys and is under 200mb. Both of these are restrictions. If you have too many polys just use the decimation master to knock that poly count down.
8. If you upload and get an error such as “surface area must be greater than 0” or “Model volume equal 0”. These are generic errors that tell you there is a hole in your mesh somewhere. This is not the hole you did to hollow out the model. These are some polygons somewhere that for some reason have disappeared. No problem though. Go through all your tools one at a time and in the geometry palette menu select “close holes”. If this does not work you may have to use a 3rd party program such as www.netfabb.com/basic.php
This is an easy program to use … just do the repair functions and that will close the holes. BE AWARE though that after you use this program it might strip your UV maps. So this really is a last step to close those holes. If that happens just import the model back into zbrush and re-apply UV’s (I used “merge similar groups” to polygroups. This helped me separate everything and re-apply UV’s to each polygroup really fast.)
9. Upload your model and look at the scale. This is why it is important to set the scale inside zbrush. This way when you upload and select the material. It gives you the price right off hand of what you really wanted. You can use the sliders to adjust the scale, although just use either the percent scale OR typing in new dimensions for your model in one of the boxes. It will re-adjust the other dimensions for you. This way is probly more accurate as I did encounter some errors with just using the percent scale. It does take some time to recalculate your price so be patient.
10. If you want to save your models online at Kraftwurx you will need a paypal account to set up your account. If not once you purchase your model you will be asked to enter in a username and password so that you can get back in and check to see what the progress is on your order.