Polylactic Acid is a polymer plastic made from biological materials such as cornstarch or sugarcane. It is similar to the material used in biodegradable plastic packaging. It melts between 180 – 200 degrees C, depending on other materials added to it for color and texture.
PLA is tough and resilient but not as heat tolerant as ABS. It begins to deform at temperatures higher than 60 degrees C. It is also not water or chemical resistant. There is a slight smell when it is heated but no toxic odors or vapors.
Because PLA is easier to print with than ABS it is usually the preferred option for low-cost 3D printers. It sticks well to a base covered in white glue or blue painter’s tape, meaning a heated print bed is not needed.
PLA lasts a long time under normal conditions. It is biodegradable and breaks down when buried in the ground. It is not, however, food safe and is a bit brittle. Prints can shatter under stress. Some manufacturers make what they call ‘tough PLA’ by adding chemicals, creating PLA that is less brittle and more heat tolerant.
It works well for general manufacturing 3D printing and painted miniatures.