Why would these classroom chair pockets have open bottom corners?

Question

I am trying to make some chair pockets like these:

http://www.reallygoodstuff.com/product_details.aspx?item_guid=2a7247de-e376-4236-9502-adbd9f23c15e#

I've got it mostly figured out, except I'm trying to figure out if I want open bottom corners. What is the purpose of this?

Answer 1

By the look of the design the large pocket is for books and the smaller pocket is for other stationery.

If you only want the children to store books in the large pocket then go with the open bottom corners. It will help prevent a vast accumulation of fluff, rubbers, broken crisps, pieces of paper etc. the alternative is having to regularly turn the bags inside-out to clean out debris.