Base layers
Scored on weight and warmth.
Base layers we've scored
Peter Storm Men's Long Sleeve Thermal Crew Baselayer Top
Weight5
Warmth5
OEX Men's Zephyr Long Sleeve Baselayer Top
Weight5
Warmth3
Rab Men's Sonic Long Sleeve Tee (Dryflo Air, Beluga)
Weight10
Warmth1
OEX Men's Barneo Long Sleeve Baselayer Top
Weight5
Warmth5
Montane Men's Dart Long Sleeve T-Shirt (APEX, black)
Weight9
Warmth3
Odlo Active Warm Base Layer Top (men's, current version with HeiQ Mint)
Weight5
Warmth3
Mountain Equipment Ignis LS Men's Zip-T
Weight8
Warmth3
Montane Men's Dart Zip Neck T-Shirt (APEX ECO, black)
Weight8
Warmth3
Montane Men's Dart Nano Long Sleeve T-Shirt (APEX Lite, regular fit)
Weight10
Warmth3
Berghaus Men's Ivyhill Light Long Sleeve Tech Tee (S.Café polyester, Archive Black)
Weight9
Warmth3
Peter Storm Men's Merino Long Sleeve Baselayer Top
Weight5
Warmth5
Rab Men's Sonic Long Sleeve Zip (Dryflo Air, Beluga)
Weight10
Warmth1
Mammut Ducan FL Longsleeve Men (1016-02060)
Weight9
Warmth3
Montane Men's Alhena Long Sleeve Merino Blend T-Shirt (drirelease WOOL, 11% merino)
Weight6
Warmth5
Mountain Equipment Glace Men's Hooded Top
Weight7
Warmth3
OEX Men's Kelso Merino Long Sleeve Baselayer Top
Weight5
Warmth5
Berghaus Men's Farndale+ Long Sleeve Half Zip Tech Tee (Jet Black/Hale Navy)
Weight2
Warmth3
Odlo Performance Light Base Layer Top (men's, current version with HeiQ Mint)
Weight5
Warmth3
Montane Men's Alhena Merino Blend Hoodie (drirelease WOOL, 11% merino)
Weight5
Warmth5
Alpkit Men's Aztec Long Sleeve (merino blend, Outer Space)
Weight7
Warmth4
Mountain Equipment Cerrig Men's LS Zip T
Weight4
Warmth6
Icebreaker 125 Cool-Lite Sphere III Long Sleeve T-Shirt (men's, size M)
Weight6
Warmth3
Berghaus Men's Delta Long Sleeve Tech Tee (Polartec Delta, black)
Weight7
Warmth5
Montane Men's Dart XT Thermal Zip Neck Long Sleeved Top (Apex Thermo, black)
Weight6
Warmth5
Odlo Active X-Warm Base Layer Top (men's, current version with HeiQ Mint)
Weight5
Warmth3
Montane Men's Dart XT Thermal Hoodie (APEX Thermo, regular fit)
Weight5
Warmth3
Rab Men's Syncrino Base Long Sleeve Tee (Syncrino 125 merino blend, Graphene)
Weight8
Warmth3
Icebreaker 175 Everyday Long Sleeve Crewe (men's, size M)
Weight8
Warmth6
Odlo Performance Warm Base Layer Top (men's, current version with HeiQ Mint)
Weight5
Warmth3
Alpkit Men's Kepler Zip Top (100% merino, Charcoal)
Weight6
Warmth5
Montane Men's Malli Long Sleeve Merino T-Shirt (core-spun merino, 84% merino)
Weight8
Warmth5
Mountain Equipment Switch Base Men's Zip T
Weight9
Warmth3
Berghaus Men's Theralite Half Zip Tech Tee (autumn 2026)
Weight6
Warmth3
Mountain Equipment Aiguille Men's Hooded Top
Weight1
Warmth6
Icebreaker 200 Oasis Long Sleeve Crewe (men's, size M)
Weight6
Warmth7
Icebreaker 175 Everyday Long Sleeve Half Zip (men's, size M)
Weight7
Warmth6
Smartwool Classic All-Season Merino Base Layer Crew (men's)
Weight8
Warmth5
Icebreaker 200 Oasis Long Sleeve Half Zip (men's, size M)
Weight1
Warmth7
Páramo Men's Grid Technic Baselayer
Weight4
Warmth3
Smartwool Classic All-Season Merino Base Layer 1/4 Zip (men's)
Weight7
Warmth5
Icebreaker 260 Tech Long Sleeve Crewe (men's, size M)
Weight1
Warmth9
Montane Men's Malli Long Sleeve Zip Merino T-Shirt (core-spun merino, 84% merino)
Weight7
Warmth5
Arc'teryx Men's Rho LT Crew Neck (Torrent fleece, long sleeve)
Weight5
Warmth6
Icebreaker 260 Tech Long Sleeve Half Zip (men's, size M)
Weight1
Warmth9
Arc'teryx Men's Rho LT Zip Neck (Torrent fleece, long sleeve)
Weight4
Warmth6
What we score
Weight
From maker's figuresHow much it adds to your pack.
Warmth
From maker's figuresHow much the fabric insulates next to your skin. Heavier fabric is warmer and slower to dry.
Comfort
From reviews, or the maker's specsHow soft and comfy it feels next to your skin.
Odour
From reviews, or the maker's specsHow fresh it stays after days of wear; higher is fresher.
Drying
From reviews, or the maker's specsHow well it wicks sweat away and dries.