Advance let me say that I support only cases of CDs, DVDs, video games and Blu-Rays with the props! So for supporting heavy books I can not say anything. The bookends are kept quite simple in design. But what is not a criticism, because I like simple design. They fall to barely meet their job but properly! The workmanship is very good, the supports are stable and the edges are rounded. Conclusion: I can highly recommend the supports, if you want to support DVDs & Co!
