The "Blue Peter" fanatic strikes again ( a children's magazine programme with handy hints ) here is a relatively cheap way, it
doesn't cost a thing, to convert a throwaway box. The boxes are from dog biscuits, it fits 4 to 5 600' spools, depending on if you use dividers. it is just a case
of measuring up the box to make it square, draw a line around it, split the corners to the line, fold, cut one of the large flaps off
and either cover with paper or paint, I just used blackboard paint, labels later. The card used in these boxes is very high quality,
sturdier than the ones used by Derann, so for a cost of nothing, a decent covering for your film, and brownie points for recycling.
Time taken, no more than ten minutes including painting.