What kind of trellis is best for climbing roses?

Obelisks and tall arches dominate the climbing-rose discussion in the r/Roses threads surfaced here. Reviewers stress that roses are trained at roughly a 45-degree wrap around an obelisk rather than straight up, so a sturdy 5- to 6-foot obelisk with a wide base often outperforms a flat wall trellis for a single specimen plant.