Abstract
The new manufacturing technology called the rapid prototyping (RP) or layered manufacturing can fabricate very complicated solid objects fully automatically. RP industry is now growing quickly and new additive methods of manufacturing are coming along. Among many types of RP which have been put to practical use by this time, the system using liquid photopolymer and a laser beam is called "photo-shaping" or "stereolithography", and nowadays most popular. Here, the principle of it is first described. Then the newly proposed methods using liquid polymer are introduced. These aim to lower the cost or to enhance the ability of the systems. Finally characteristics of the resin necessary in the application of the solid models are pointed out.
