This article discusses the properties and applications of two types of polyimide resins: condensation polyimides and addition-type polyimides. It describes the chemistry of condensation-type polyimides during synthesis, processing of polyamide acid precursor solution to polyimide, and preparation of polyimide films from thermoplastic polyamic acid precursors. The article reviews the chemistry of several addition-type polyimides, including phenylethynyl-containing imide oligomers, nadic end-capped polyimides, and LARC RP46. It explains the preparation processes of nadic end-capped amic acid oligomer resin solutions, including the preparation of resin powder and resin disks, adhesive film, adhesive bond specimens, and films.