3D Printing can be done in a myriad of materials, depending on the machines available and the needs of the project.
Made from renewable resources, Polylactic Acid is a green 3d printing material. It is a slightly flexible material, but it generates a smoother outer shell of the printed object. Due to the fact that it is made of corn starch, PLA is not toxic and releases a pleasant sweet smell. PLA is preferred for 3D printing smaller objects. However, the material is not very sturdy and can warp in exposed to heat.
The material can be used for a lot of applications and is widely available. It often serves as a lighter alternative to glass. It is shatter resistant and embodies range of durability (from flexible to hard) depending on the version of resin being used. It must be cured with a UV light but can be used to produce a variety of colors.
Printing with metal produces a very strong and rigid object, but requires many steps and a long printing process. It does not show very small details, but can be polished in post-production to take away the signs of 3D printing.