Powder printers, which lay down a thin layer of powder and then use a binder fluid to bond the object together, are now being built by the home hobbyist community. One of the factors limiting their usefulness is the powder being used as raw material.
Most commercial printers use proprietary materials in their print beds and they tend to be very expensive. Now that people are building their own machines there is a lot of interest in developing cheaper materials that can be created at home. There are a number of recipes for different powders out there for use in diy powder type printers. A lot of them, and the best of them, come from Open3dP (Open 3d Printing) at the university of Washington, though there are also a few others that I have seen on various forums.
I have collected as many of them as I have encountered in a single document which I am making available to anyone who might be interested. There is nothing revolutionary about this document. I will just save you the time of looking back through all the blog articles if you are trying to remember a formula. As time goes on I expect many people to be experimenting with different materials and I will update this document as I discover new information.
None of these recipes are my own. They are all the result of hard work done by other, smarter people so I can't answer any questions about them. Until I get a powder printer built I am not even able to try them myself. There is a lot of additional information available on the open3d site. That site is maintained by Professor Mark Gantor who has been very helpful in creating this document. Thanks to him especially for advising on how copyrights and proper credit should be handled. The Open3dP site should be the first stop for anyone experimenting with materials for powder printing.
For what it's worth, I offer this up to the powder printing community. The information is all in the public domain but the pictures are copyrighted by Professor Gantor. If you want to use the text in other documents please give proper credit to the original creators. The recipe book is in MS Word format and can be found here.