Who doesn’t love fleece jackets? They’re soft, warm, breathable, and incredibly versatile. Throw one on as an outer layer on chilly mornings or wear one underneath a heavier outer layer when the weather gets cold. I have a few in my closet that I’ve had for years, and while they don’t look as sharp as they once did, they still feel like old friends when I put them on. There’s even an environmental reason to feel good about fleece since some manufacturers are now making their material out of recycled plastics. Here are three tips to get you into the fleece jacket that’s perfect for you.

How Materials and Weights Work

Front-zip fleece jackets like this are easy to toss on and take off. This jacket is designed to fit close to your body to move with you. The secure chest pocket is a perfect place to stash your phone. Starter

It’s hard to believe that a garment that is so fluffy and soft can actually be woven from recycled plastics, but the polyester material that fleeces are made of is just that. Plastics are broken down and extruded to produce soft fibers that are woven into fleece fabric. Because the fibers are made from a petroleum product, they don’t absorb water. This gives fleece insulation a huge advantage over down, which loses its insulating qualities when it gets wet. Fleece comes in a variety of weights, so you can choose the weight that suits your activity level. Lighter fleeces are more breathable than heavier, thicker fleeces, so don’t just go for a heavyweight fleece unless you intend to use it solely as an outer layer when you’re not hiking hard or exercising.

Fleece is categorized by weight in grams per square yard of fabric. The higher the g/m² factor, the warmer the fleece will be. Here’s how the weights break down:

Ultralight: less than 100 g/m². Perfect as a base layer or even by itself if you just need a light layer to go running in.

Lightweight: 100 g/m². The ideal base layer or you can wear it as an outer layer to work out or hike in. Throw a vest on top and you’ll be toasty warm.

Midweight: 200 g/m² Here is your most versatile fleece. Wear it as an outer layer on cool days or as a mid-layer when it gets cold. Pair it with a vest and a water/windproof outer layer and you’ll be ready for anything.

Heavyweight: 300 g/m² and up. Use this for lounging by the fire (not heavy exercise) or as an outer layer for the coldest weather.

Breathability Is Key

This mid-weight fleece can easily be worn as an outer layer on cool days or as a comfortable base layer when cold weather comes. Elasticized cuffs help keep cold and snow out. Amazon

Breathability is probably the biggest concern outdoor enthusiasts have about garments. Back in the day, fleece wasn’t very breathable, but with modern innovations that have produced “micro-fibers,” fleece now rates as one of the most breathable products out there. Manufacturers have also created new designs that utilize lighter-weight fabrics in key heat-producing places, like armpits, to increase breathability while using thicker fleece materials to keep your core warm. Don’t mistake breathability for windproofness, however. Unless your jacket has a breathable inner or outer layer that stops the wind, fleece by itself does not protect well against the wind. On windy days, wear a lightweight windbreaker on top and you’ll be all set.

Choose the Right Jacket Type

This jacket is lightweight yet super warm. Sizes range from ES to XXL. Buy your fleece jacket a little larger if you plan on wearing a vest underneath. Columbia

Fleece jackets come in a variety of weights—each designed with an outdoor purpose in mind. Here’s what to look for:

Lightweight Styles: These jackets are super versatile because they double up so well as either a warm mid-layer during cold days on the ski slope or as a lightweight top for a walk in the woods on a cool fall day. Lightweights are generally more slim fitting and breathable. Hooded and/or pullover styles will be warmer because you don’t have a full front zipper that can create a cold spot.

Midweight Jackets: Perhaps the most versatile fleece of all. Midweights work great on their own worn over a sweater or shirt. They also provide a thicker mid-layer when you’re pairing them with other garments to layer over the top. A note to skiers and snowboarders, you’ll probably want to steer clear of hooded midweights as hoods can’t fit under ski helmets.

Heavyweight Fleeces: Headed for Everest? This is what you want. Heavyweights are super thick and warm, but they’re not very breathable. Definitely a great garment for lounging around the fire or wearing as an overcoat to work, but you will overheat if you do any kind of exercise with a heavyweight on. Save it for those brutally cold days when you really need something heavy on.