They say "dress in layers"โwhat does that mean when it's rainy? Itโs easy to say โthereโs no bad weatherโjust bad gear,โ but itโs another thing to know how to use said gear properly in gnarly conditions. Like, when the mist on your backpacking trip turns into an all-out waterfall and you have to decide what layers will keep you most comfortable while youโre moving quickly uphill. Itโs easy to say, โdress in layers.โ But what layers exactly does that mean? Knowing how to layer with a rain jacket can make a huge difference in comfort and morale. Here are five tips from Alex Lauver, our director of commercial innovation, on what to wear under your rain shell for maximum performance. Start with the best base layer and mid layer. โGenerally, I like to wear synthetic if itโs really an extended time outside in wet weather or if Iโm generating lots of sweat. In the city or in more static activity in just โdampโ weather, I will wear a light down layer underneath (Iโm a sucker for down). Fleece and grid fleece style mid layers perform pretty well under a shell, too! They trap good air for insulation but also breathe and move moisture very well. They may not be the best choice in really, truly cold conditions, though.โ READ: Getting The Most Out Of Your Gore-Tex Rainwear Then ask, โHow hard will I be moving? And, โWhat conditions will I be likely to see?โ โSomewhere in there, too, is durability and how far from shelter will be. Very generally, I think of 2.5L shells as the โfast and lightโ option, and 3L as โI could be wearing this all day.โ That extra layer [on a jacket with 3L fabric]โa tricot or warp knit usuallyโis actually a textile, so the next-to-skin comfort is much better in general than 2.5L shells. However, 2.5L shells are generally lighter and more packable. Consider humidity, too. โIn moderate to high humidity environments, anything that doesnโt mechanically vent (being air permeable or microporous) wonโt perform as well as related to comfort โฆ Itโs important to also point out that โmechanicalโ venting could mean pit zips. That overcomes a large amount of membrane slow down.โ Pick the right shell. โThe Helium is a killer emergency/squall type shell where Iโm likely to only need it for short periods, or as a emergency backup shell,โ Alex says. โThe Foray/Aspire jackets are the awesome durable choice if itโs going to be soggy but Iโm maybe not charging super hard, or generating lots of sweat.โ READ: How To Wash Gore-Tex The new Motive AscentShell Jacket is a streamlined three-layer option thatโs both flexible and breathableโpossibly our most versatile rain jacket. Itโs a no-frills option thatโs high on function, focused on features made for performance without weight. The Microgravity Ascentshell Jacket takes that same breathable, flexible three-layer protection and adds a helmet-compatible hood and stretch panels under the arms, making it an all-sport, all-season performer. And take good care of your shells. โYou do need to wash and dry your shell once or twice a season. DWR is a component in quality rain shells that in many cases is even more important than the membrane itself. Smoke can โclogโ pores in certain types of membranes. And basic wash/dry care does a lot to prolong life and keep performance optimized.โ READ: How To Wash a Rain Jacket. SHOP THE RAIN COLLECTION