SP, Southampton Institute etc etc ,they must be wrong! One for your tool face ,one side for your cloth and one for the other side of the cloth .I make that times three.I said times 2.8 to 3.0 What do you build? .Bloody hell.
take it easy. no need to huff and puff over this.
do you really believe that when you manufacture a 1m^2 composite panel [fibre/foam/fibre] with 500g/m^2 fibre each side of the foam, that you need 3kg of resin to do so?
when i worked for SP-Systems in Germany back in the 90's we wouldn't have recommended 3kg and in my own composite manufacture company that i have been runnin for 5 years now i would use around 1kg [depending a bit on how coarse the pores in the foam are].
i would always recommend to buy a bit more resin than you think you need to cover all those "little accidents" that happen. you sure don't want to be stuck in the middle of the process with no resin left because you tipped the cup over...
good luck and always wear protective gear when working with compsite materials.