Skins treated with sulphuric acid. How can I recuperate the skin elasticity ?

[JANY]

I received several skins from Argentina treated with sulphuric acid. Those skins seem like cardboards. My question is : How can I get softer and recuperate the skin elasticity to mount it?

Thanks for helping me.

[oldshaver]

Was my first response too difficult? If you need real novice answers, let us know. Sometimes we assume everyone everyone has basic tanning knowledge. So you have to let us know, if you need laymens terms, or simpler instructions. Treated with sulphuric, do you mean pickled? What are the skins? Tell us more. Most arent willing to answer, without more info. Your not going to get more stretch, without getting the skins wet, if thats what your getting at.