Leather is iffy. We’ve tested in on different leather surfaces and in some cases, it’s been fine. The issue is that some leather dye used is weak and will bleach out when cleaned with Eco. What we tell our customers with regards to leather is pre-test it in an inconspicuous spot, like an underside cushion, at a 15:1 concentration.
We are really risk-averse here at Eco Orange, so we’d probably error on the side of safety and say NO, don’t use Eco on that beautiful leather couch.
One final friendly reminder: Never use Eco on silk, satin or suede – the 3 S’s.