What kind of jersey for summer heat and sun? With summer on its way, I'm looking for kit that I can wear in the summer to keep myself cool.  My typical routes don't have a lot of shade. What should I be looking for?  I know I am going to want a full-length zip, but what else?

Are there jerseys that are designed for this?
What about types and colors of fabric?
Is it better to wear long sleeves to keep the sun off, or short to allow sweating?
This is a matter of personal preference. I live in a hot climate. I've worn everything from sleeveless jerseys with perforated backs to long-sleeved jerseys in hot weather. My current preference is for long-sleeved jerseys, in order to get the added sun protection. There aren't a lot of lightweight long-sleeved jerseys, but there are some, and some advertise their SPF ratings.
Some clothing manufacturers advertise &quot;coldblack&quot; jerseys (black, but intended for hot weather). I've never tried one, and I'll admit I'm skeptical they'd be comfortable. I always wear lighter colors.
Jerseys are designed to wick sweat and breathe well. Modern performance textiles are pretty amazing.