Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4879203 | Process for producing masked positive color images by the silver dye bleach process | — | 1989-11-07 |
| 4868098 | Method of processing exposed photographic silver dye bleach materials comprising heating after processing liquid application | Rolf Steiger | 1989-09-19 |