2015-03-19 // 14:45:44 g. I see. The white part became more stubborn so now we need bleach. Merci!
2015-03-19 // 11:43:25 g. but you bleach the black backing of the negative, like with 100c, not the front with the white product, right?
No no, it's different from the 100C. You can't remove the black stuff with IP films. You have to bleach the white part.
And prepare to be fast.
2015-03-19 // 10:58:25 g. which film exactly was this? I've tried a color 600 goldroundframe with exp. 11-15 - rien. Neither with a bw600 roundframe 10-15. I can peel both, wash them and get soft negatives (softer than in earlier times, looks like they fade even inspecting them this morning), but the black backing is resistant to bleach.
This is a normal Impossible color film for SX-70. You have to open the picture, keep the image for lifting (for instance) and bleach the other part of the image (covered by a white product). And then... it works.