Item Attributes
armorTexture
This attribute defines the texture of the armor when wearing it. If the value of this attribute starts with a '/', the texture is loaded from minecraft.jar. If it doesn't start with a '/', the texture is loaded from the mod's texture directory. For a whole armor (helmet, plate, legs and boots) you need two texture files. One is for the helmet, plate and boots and one is for the legs. Examples for those textures can be found in the minecraft.jar/assets/minecraft/textures/models/armor directory. The files that end with '_1' are for the helmet, plate and boots and the ones that end with '_2' are for the legs. If you want to make for example an armor set that looks exactly like the golden armor set, you have to set this attribute to "/gold_1.png" for the helmet, plate and boots and "/gold_2.png" for the legs. Texture files for this attribute go into the assets/{mod name}/textures/models/armor directory of your mod.
Examples
armorTexture = "tin_1.png;
// Uses iron_2.png from the minecraft.jar.
armorTexture = "/armor/iron_2.png";