I always order 2 extra foams for every kit because once i start i don't want to stop.
Always nice to have extra refills on hand....can make the shakers up before hand and have them ready..or just to know you have them when they sell out....LOL
I always buy multiple packs of the refills! they are good to have on hand and i teach classes so i use a lot!
I've never tried to cut my own foam and acetate. I always order refills when ordering a kit. Having extra assures me if I need to make more, I have them without trying to make more on my own The quality of the foam can't be match, nor the thickness. Knowing I won't have any issues is priceless.