I think palimpsests were usually made using parchment
(leather). I think paper and papyrus were probably too fragile.
The use of lemon juice or urine could fade out ink on papyrus and paper. Paper in Rome was a thick product and there was also ‘bark sheets’ to write on. Roman ‘garrison lists would sometimes arrive on bark sheets which were reused by putting a mild acid on the ink to fade it out. Much later underlying ink stains would come up into the above inks. Sheep skins were the most expensive to write upon but very durable for reuse.