"3D printing continues to get better and cheaper every day. It also is becoming more accessible to casual users and artists. One of the great services offering 3D Printing to you and I is Shapeways. Shapeways allows you to not only get your models printed, it allows you to create an online shop to sell your own models. It's like the Etsy of 3D printing.
However, preparing your models for 3D printing has it's own set of requirements. You need to take into account the physical size of the model. Is the model solid or hollow? How thick are the walls? Will the form support its self in the chose material? Among other things, these are just a few of the bits you need to keep in mind when preparing your model for printing.
This tutorial takes you through the process of preparing Suzanne, Blender's monkey mascot, for printing from start to finish. You'll learn how to work with real-world measurements, how to hollow out the model, how to check for non-manifold meshes, how to make an escape hole, and more."