I've cut 4x5 down to fit my 9x12 holders but I found it was a pain due to the small amounts that need to be trimmed. 5" is only 7mm long for the 9x12 holder. The roller cutter must be very sharp, your marker must be accurate and you have to hold the film tightly without scratching it. Perfectly possible but not, in my humble opinion, worth it. Cut from an 8x10 sheet or buy fresh film.