Indeed cheaper karategi are often cut from a light fabric similar to a summer shirt. These karategi are easily ripped, and tend to adhere to the practitioner's skin, creating some discomfort after any extensive perspiration is experienced. Such karategi material is no heavier than the 8 oz weight fabric.
Most quality karategi are cut from a light canvas style cloth which will stand up to a considerable amount of abuse without restricting the mobility of the karateka. Typically, such karategi use at least a 10 oz cotton canvas, and can stand up to more rigorous applications.
The advanced practitioners seem to favor the use of a heavier fabric. 12 or 14 oz cotton canvas is usually the norm, although some manufacturers offer 16 oz materials, and some karategi manufacturers will use another processing step to brush the cotton canvas, creating a more comfortable feel. Despite the extra weight of the heavier fabrics, most experienced practitioners prefer them due to their durability, and the ability of the thicker fabric to wick away perspiration. It is not unusual for a martial artist to feel better cooled when using a heavier karategi, compared to the cheaper karategi (often referred to as paperthin gis).
Different styles of Karate have slightly different uniforms though all share the same basic design, differing only in the lengths of sleeves, legs and the skirt of the uwagi (jacket). Many karateka tend to wear their Obi (belt) much longer than judoka and other martial artists.