A recent visitor/reader just asked me this question. Although i have described 'Dragon Skin' before i will do so again.
Basically about 4 years ago now when i got back into paper mache the first thing i wanted to do was make dragons. More specifically back then just large wall mounted dragon heads. Having 6 children now mostly all grown i KNOW the last thing you want free hanging on a wall is something that can fall & be heavy enough to cause serious injury. Ordinarily paper mache doe's not need to be several inches thick to be strong. It is by it's very nature a light weight material that becomes lighter over the years as it continues to dry out. How ever i wanted MY art to be even lighter still from the start.
So after applying a little knowledge of certain materials both easily purchased cheaply as well as already available around the house along with wanting to make my art on a 'shoe string budget' basis for artists who may be doing art with limited funds. I came up with a flour, water & PVA glue mix that i used to cover as few as 6 to 8 layers of paper mache (news print) that was as strong as most any 15/20 layers of paper combinations. Not knowing anyone else having done this at the time & needing a way to describe it, because i created this mix for my 'then' large dragon heads i simply named the mix 'Dragon Skin'. Now i apply it to anything paper mache that i want to make as strong & as light as possible using as little paper as possible. Naturally on doing so i then coined the phrase "Dragon Skinning".
ie: I will NOW be 'Dragon Skinning' this skull to give it a smooth & bone hard finish that reduces the need to sand it before painting.
I have since then perfected a way to 'grow' texture (YES GROW as it dries grow) in the dragon skin with a result that is something akin to toad skin. NO THAT recipe IS secret & will NOT be revealed here!. As well as make Dragon Skin so when dry it is as hard & smooth as to ressemble bone. ie: My 'bone mix Dragon Skin.
You can learn how to make Dragon Skin right here with my YouTube HOW TO video: