Someone had said that Arista 4x5 film is a thinner Ilford. I just ordered some f rom Freestyle and was told that it is 4 mil while all of my other 4x5 is 7 mil. So it is thinner than most Kodak but I don't know how thick Ilford HP & FP is.

Is there anything I need to know when using the 4 mil film?

BTW, I miked a number of sheets of Kodak and most are .0082 - .0085".