A mess tin is an item of mess kit

Mess kit

A mess kit is a collection of silverware and cookware used during camping and backpacking, as well as extended military campaigns.-Civilian camping mess kit:...

, designed to be used over portable cooking apparatus. A mess tin can be thought of as a portable version of a saucepan, intended primarily for boiling but also useful for frying. Mess tins were originally a military design, but are also popular among civilian campers.

Design

Mess tins are generally rectangular with rounded off edges - the rounded edges are easier to clean inside than a sharp corner. Most mess tins are supplied as a set, with one slightly larger than the other, allowing them to nestle together for easy packing. This arrangement is also useful when using the tins for boiling, as the smaller tin can be used to hold the liquid, with the larger tin placed on top to act as a lid. In order to save weight, some designs stick with a single mess tin with a lid, with the lid often having a secondary role as a frying pan.