The inside paddings was made of 5mm thick EVA foam. It's soft material, that is used for youga mats and tourist gear. It can be easily shaped and rigid enough to stay in place. Same time it's skin friandly, so no covering is required.
At first I cut out of the foam sheet some pieces to cover the place inside of the mask with 1 layer. The parts are not need to fit each other precisely. Moreover, there are need to be some gaps to allow some air ventilation. The paddings was secured using hot glue.
I did not cover the front part of the mask totally. Actually yo don't need to do it unles you don't want to muffle your voice as it is ever possible. I just put paddings at the chin area, cheeks, nose and forehead.
When the first layer was complete, I started to install comfortizing paddings (this time I put just one leyer on, because I don't know what the head sises are. Alsi I think that only wearer himself can comfortize him, because nomber of paddings of each position isn't something standard.
I prepared a nomber of paddings by two shapes: square and line. The square shape is for cheek paddings only. There can be from 4 to 7 layers and you must place equal quantity to each side. The line shaped are for the forehead and back head placing. I recommend to place them first, and only after you feel tight enough that the mask don't move front- and backwards, start to install cheek ones. Also every padding placed to chin area will shorten character's neck. So one is enough.
There is two sided duct tape on one side of each padding. If you're experienced enough, you can shape padding's curvage using the duct tape. Also it nicely secures peddings at each other.
My own mask paddings count is 6 per cheek, 4 per forehead, 6 per back head.
