Creating a cozy, insulated layer that’s breathable takes a village, and the PROOF design team confidently rose up to the challenge. The AltoLoft Insulated Shirt Jacket delivers on-demand warmth in a style-friendly jacket cut—ideal for city-to-trail travel. Its nylon shell is treated with a durable water repellent (DWR), and blended with a touch of spandex to help the jacket keep its shape and allow gentle flex. For the insulation, a 40 grams of PrimaLoft insulation is tapped, helping keep the jacket as breathable as possible without sacrificing warmth, while also delivering water-resistant insulation that’s lighter and tougher than traditional down. (By the way, PrimaLoft was actually first developed for use by the US Army in the early 1980s, and the insulation worked so well that outdoor brands poached the technology for themselves). Combine all these technical elements with the fact you’ve got a pack-friendly design (it can roll up for storage in a day bag), ample pocket space, and a soft quilted liner, and you’ve got a damn good snap layer that’s up for anything.
Features
Durable water repellent exterior (DWR coating)
Quilted Interior
Concealed front zipper pocket on left chest
2 front side entry pockets at waist with zipper closures
Hanging locker loop
Materials
Body: 94% Nylon, 6% Spandex, 118 GSM
Lining: 88% Nylon, 12% Spandex, 95 GSM
Sleeves: 100% Recycled Polyester
Insulation: 40g PrimaLoft
Sizing
The AltoLoft Insulated Shirt Jacket has a regular fit that’s true to size, take your normal size
For the absolute best personal fit, compare your best-fitting jacket to the garment measurements below
Garment Measurements
XS
S
M
L
XL
XXL
Chest
41
43
45
47½
50
57½
Shoulder
18
18½
19
19⅝
20¼
21⅛
Body Length
27¾
28¼
29
29¾
30¼
31
Sleeve Length
34
34¾
35½
36¼
37
37¾
All measurements are in inches.
How to Measure
- Garment Chest: measure on a shirt from side to side starting 1” under the armpit, multiply by 2
- Shoulder Width: measure on a shirt straight across the shoulder from seam to seam
- Body Length: measure on a shirt from the high shoulder to the bottom hem
- Sleeve Length: measure on a shirt from the center back to the cuff opening
Care
Machine wash cold on delicate cycle with similar colors
Do not bleach
Hang to dry
Iron low heat
About PROOF
Sprint and catch that train. Bike to your next meeting. Stretch out on that international flight. Thanks to innovative technical fabrics and thoughtful design, PROOF's clothing is smart, technical apparel rises to every occasion. Designed for work, play, and travel, PROOF updates everyday essentials with the latest performance fabrics and construction techniques to help you get more out of your clothing — so you can get more out of yourself.
