If I may suggest something, I think you should avoid having the upper shelf hanging on screws/glue. Maybe have a gap in the bottom divider, about 2/3 of the way back, and have a vertical support from shelf-to-shelf there? Looks like you could squeeze that out of the sheet. You could do some triangle supports out of the remaining scraps for even more strength. P.S. about 12-1/4" for a jacket. Some are larger. 12.5" is probably the min. width you'd want the actual shelf space... hmm..