you can use cheese cloth, cut into strips and dipped into the latex to reinforce. works just like plaster bandages
For what it is now worth I am also recommending the cheesecloth and latex route. But when that advice already comes from fettster and The Batman you know it's good.:thumbsup
You need to make sure the mask you're trying to reinforce is latex to begin with, Rubies uses mostly vinyl on their new masks these days, and latex won't stay adhered to vinyl.
I haven't seen one of these up close so I can't say for sure.