A 4-inch 80-ppi flexible AMOLED display was fabricated using organic TFTs with an inkjetted semiconductor layer on polymer gate insulator film. To suppress variations in organic TFT (OTFT) characteristics, the process damage to polymer gate insulator was remedied by surface treatments, and organic semiconductor crystallinity was improved by controlling the film thickness, giving a threshold voltage uniformity of -0.2 ± 0.45 V. We also observed the non-degradation of the OTFT characteristics even after bending it 200 times over a 5-mm radius.