Stackable filament spool shelf

this is my design for a fully printable stackable filament shelfing solution. it fits spools of all sizes and weights. it is  strong enough to stack over 12 full 1kg spools up on top of one another (it can stack more however i do not have any more spools).  Each shelf uses 200g of filament, i recommend printing in PETG however it will work in PLA or alternatives