Shape Field Guide
Every silhouette term in the book, with its use case and its cost.
- Volume
- 04
- Order
- № 10
- Read
- 2 min
- Tags
- appendix · inventory
- Published
An at-a-glance reference of the silhouette and geometry terms used throughout this book. Each entry: one-line use-case note, one-line cost note. These are the book’s working geometric descriptors - not ISO or ASTM standardized categories.
Geometry cheat sheet. Illustrative only.
| Term | Profile description | Primary use case | Primary cost |
|---|---|---|---|
| Slab | Panel-dominant; width and height large, depth small; flat rectangle in silhouette | Laptop commute; messenger carry; under-seat documents | Limited volume per unit of back-panel area; distorts under bulky load |
| Structured | Padded or framed sides maintain shape when empty; holds a trapezoid or box profile at rest | Camera bags; structured totes; travel packs where predictable geometry matters | Weight and bulk even when empty; does not compress |
| Tapered | Narrower at top (or bottom); shoulder-clearance convention from hiking-pack design | Trail daypacks; ergonomic commuter packs | Rectangular items (laptops, packing cubes) may not seat cleanly; corner deadspace at the shoulder |
| Collapsed | No fixed shape; form follows contents; folds flat when empty | Duffels; packable layers; overflow and gym bags | No organized packing plane; access is sequential by default; load can shift mid-carry |
| Boxy | Depth approximately equal to width; square or near-square cross-section; often rigid or semi-rigid | Hard-shell camera cases; packing-cube-optimized travel bags; rigid briefcase-style | Projects far from body; heavy overhead for smaller loads; does not compress |
| Barrel | Cylindrical or quasi-cylindrical cross-section; single-opening tube geometry | Top-loaders; stuff-sack daypack inserts; roll-top travel packs | Sequential access only; retrieval order follows pack order |
| Clamshell | Three-sided zipper path; lays flat when open; full packing plane visible | Laptop bags; travel backpacks; bags needing daily organized presentation | Fixed volume; cannot compress; zipper arc requires maintenance |
| Sling | Single diagonal strap from shoulder to opposite hip; bag rotates front-to-back | Urban quick-access carry; one-bag day trips; side-entry retrieval without removal | All weight on one shoulder; lower comfortable load ceiling than two-shoulder carry |
| Roll-top | Extended collar walls roll over and secure; variable-volume closure | Ultralight travel; wet environments; variable-load configurations | Sealing requires uniform wall height; volume loss per roll is product-specific |