Polyimides are attractive candidates in microelectronics due to their high thermal and chemical stability, low dielectric constants and high dry etching resistance. However, polyimides in solution form have tendency to absorb moisture, which could lead nonreproducibility in nanometer scale patterning. Since last 10 years, we have been developing a series of solvent soluble polyimides in powdered form, by using block-copolymerization process in the presence of binary catalyst. Here, we report our developed process for customized polyimide resist formulation and on-site resist preparation prior to any lithographic applications. The results of applications of on-site mixed and prepared polyimide resists for 435 nm, 365 nm, 248 nm and e-beam lithographies are summarized in this paper. The reproducibility of high resolution nanometer scale patterns by electron beam (e-beam) could observed even after five years, using the same stock of polyimide powder using the on-site mixing process. The results are given in this paper.