substantially flat back that facilitates attachment to a smooth surface such as a wall fig3 shows a back view of the shelf system of fig1 in one embodiment each shelf 12 forms a substantially flat and horizontal support surface 2 and a surface 4 perpendicular to the support surface 2 which serves as an attachment area to the vertical support frame 14 thus the support surface 2 and the surface 4 may combine to form a substantially l shaped cross section as will be appreciated the concepts herein may be applied to shelf systems having other configurations such as those taught in u s pat no 7 494 019 the entire contents of which are incorporated by reference herein for all purposes an alternative embodiment of the shelf may include a t shaped cross section not shown a t shaped cross section advantageously increases the bonding surface area between the frame 14 and shelf with one u201c side u201d of the t shape being in compression and the other u201c side u201d of the t shape being in tension thereby the bonded strength between the frame 14 and the shelf is increased in addition the bonded area of a shelf 12 with an l shaped cross section is either in tension or compression depending on the specific application for which the shelf is used because bonded strengths in compression tend to be greater a t shaped cross section advantageously provides both tensile and compression forces at the bonded joint the support frame.