Jedi Knights in the Old Republic era are known to wear a suit of segmented plate armor underneath cloaks and robes of various earthy colors. This armor can also vary in strength, ranging from heavy plate armor to simple cloth and leather robes.
Advanced Class Specific Armor
Jedi Guardians are the only Jedi class that is able to wear heavy plate armor. This plate armor usually consists of a pair of bracers, shoulderpads, boots, thigh plates, chest plate, and abdomen guard. This aids in their functions as a heavy damage dealer and/or tank. This armor is designed to protect against blaster fire.
Jedi Sentinels are able to wear heavy robes and leathers, but shun the heavy plate armor of their Guardian counterparts. This reflects their heavy damage-dealing capabilities as dual-wielding, nimble warriors. Naturally, they are not as well-protected as their Guardian counterparts as a result.