Patagonia Puffball Sweater

Synthetic insulated jackets of this type (others are made by Marmot, TNF, Moonstone) really should be considered a third grouping (along with fleece and down) rather than a substitute for either.

Compared to fleece, they are lighter and far more compressible for the same warmth. Because of the nylon shell, they block the wind better, and tests in the washing machine show that they dry slightly quicker.

However, they are not nearly as durable as fleece (the Puffball outer fabric tears quite easily), and do not breathe as well.

Compared to down, they are cheaper, but not nearly as warm or as breathable for the same weight. However, the Puffball is less affected by wet weather--although a down jacket with a good outer fabric (it doesn't even have to be DryLoft) is not nearly as sponge-like as some claim.

The Puffball (since replaced by the upgraded FireBall) has a ridiculously small zipper pull, a very nice inner mesh pocket for drying gloves and hats, and not much else.

I've found it's best used when space is tight in a pack, or when multiple layers of fleece are too restrictive--downhill skiing at below 0 F.

A medium weight capilene shirt, an expedition weight shirt, a retro pile jacket, a puffball--all under a storm parka--works well when it's really cold.

Synthetic filled jackets of this type (also made by TNF, Marmot, Moonstone, Mountain Hardwear) could be considered as a replacement for either fleece or a down sweater, but really they fall in the middle and are best for specialized applications.

They may be warmer when wet than down sweaters, but they really aren't any lighter (for the same warmth) as down and are considerably more fragile.

As a replacement for fleece, they are lighter, more compressible, and more wind-resistant, but they are also far less durable and don't breathe nearly so well.

I use this over fleece and under a shell for really cold skiing and for knocking around town in the Montana winter. For this it's fine (adding more and more layers of fleece quickly becomes restrictive) but beware of certain limitations:

The shell is 1.3 ripstop and very susceptible to snagging and tears (especially around the seams)

The zipper is ridiculously small and easy to snag

The insulation batting tears (developing lumps and cold spots) very easily

Then again, it is mildly water repellent, dries quicker than fleece, and is warmer and lighter than the thickest pile (Patagoina retro-pile, Polartech 375 bi-polar).

You just have to be very careful with how you treat it.

This is an excellent product. It is vastly lighter and warmer than fleece, and will pack into a 5x7 stuff sack. It is almost as warm as a down jacket, but with none of the disadvantages of down.

Only complaint: the thin shell is a bit delicate (but what do you expect for something that's intended to be super light?). Wear it under a shell it you expect abuse.

This is a great jacket to put on as soon as you stop hiking and before you cool down. Packs into tiny spaces and weights nothing. It does lack a proper collar to keep your neck warm but for the portability, it can't be beat.

The fabric is a bit thin, so wear a shell if you are hiking through heavy brush.