Peak Design Capture clip backing plate for thin straps
A spacer plate that sits behind a Peak Design Capture V3 clip so it clamps firmly onto thin backpack straps, seatbelt-style webbing or a 20 mm MOLLE row that the stock back plate cannot squeeze. The Capture clamp handles straps up to about 64 mm wide and 15 mm thick; this 84 x 44 mm plate is 6 mm thick with two 5.5 mm bolt holes (measure your clip's bolt spacing, roughly 36 mm) and a 1 mm textured grip pattern so the strap cannot creep under the weight of a Sony A6700 or Fujifilm X100VI. A 3 mm rounded edge keeps it comfortable against a shoulder. Print it flat in PETG with 100 percent infill.
Instead of jamming folded card behind the clip, you give SpeakCAD your strap thickness and bolt spacing and it draws a plate that fits, previewable in the browser without paying, adjustable in the chat and then downloadable as an STL.
Model a backing plate 84 x 44 x 6 mm for a Peak Design Capture clip with two 5.5 mm bolt holes 36 mm apart, a 1 mm raised diamond grip texture on one face, 3 mm rounded edges and a 20 mm wide, 2 mm deep channel across the back for MOLLE webbing.