Photo-etched parts at 1:72 serve torpedo boats and fast attack craft above all — the vessels most often built in this large scale. Sets cover armament including the shields of rapid-fire cannon, life-saving equipment, deck and mooring hooks, and complete detail packages for named boats. The bigger the scale, the more the metal shows; here you are working at something close to macro detail, so folds and alignment have nowhere to hide.
A boat at 1:72 is a model you pick up, and a viewer looks at it from close range, so etched fineness is repaid in full. The craft themselves are among 1:72 ship model kits, while frets in all other scales sit together at ship photo-etched parts. If the vessel has a planked deck, look at 1:72 wooden decks too — at this size real grain is visible to the naked eye.
