My favorite putty! This two-part putty (putty and separate hardener) is easy to work with, has a fine "grain," doesn't shrink, and is just about the same hardness as styrene plastic when dry, so it's easy to sand and blend for seamless work. With a 5-10 minute "work" time, it dries totally in about an hour. The smell is a bit strong, but other than that, this stuff is great! Perfect for re-modeling, detail fabrication, sculpting, repairs, and kit modifications.