Zach Legacy of Fire
Light armor woven from the silk of giant spiders
Instead of leather, silk made be used instead, allowing more ease of movement and heat retention at the price of of more expense and slightly less protection. Silk can be substituted for any leather or hide based except it costs 50 GP more and is 1 AC less, +2 DEX, 1 less Armor Check penalty, 5 percent less spell casting failure, 1/2 weight, and 1/2 penalty to saves for enduring long periods of high temperatures. Masterwork versions remove the save penalty completely.