Smartwool
Smartwool Classic All-Season Merino Base Layer Crew (men's)
- Weight: 8/10 How much it adds to your pack.
- Warmth: 5/10 How much the fabric insulates next to your skin. Heavier fabric is warmer and slower to dry.
Spring, summer and autumn hill days, and wild camps where nights stay above freezing
- Weight
- Not published
- Fabric weight
- 150 g/m²
- Fibre
- Blend
- Merino
- 88%
Where to buy
Smartwool £79.99 In stock. Free delivery. Black, size M. Free delivery over £55; 30 days free returns.
View at shop: SmartwoolPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight
Estimate from maker's specs: fabric weight (no garment weight published) 8/10How much it adds to your pack. 8: Clearly better than most.
Estimate from maker's specs
Warmth
From maker's figures 5/10How much the fabric insulates next to your skin. Heavier fabric is warmer and slower to dry. 5: Does the job. Average for wild-camping gear.
Smartwool's US page for this top (code sw016952) lists the fabric as lightweight, 150 g/m², the bottom of the 150–189 g/m² band: a three-season layer, not a winter one. The UK page (sw016953) gives no g/m² figure, so the US page is the source. It is the same top: both pages describe the same 88% merino and nylon-core jersey and the same flatlock and offset seams, and the codes differ only by market.
In short
Good for
- Spring, summer and autumn hill days, and wild camps where nights stay above freezing
- A light merino layer for sleeping in and for layering under a fleece or insulated jacket
- Multi-day trips where you can't wash it: reviewers found it stayed fresh unwashed
- Anyone who wants a relaxed fit rather than a skin-tight one
Strengths
- 88% merino with a nylon core, so more durable than thin pure merino, says Smartwool
- Merino against the skin, so odour stays low over several days of wear
- Seams rolled over the shoulders to stay clear of rucksack straps (Advnture, CleverHiker)
- Relaxed fit that layers easily under a fleece or insulated jacket
Weaknesses
- Smartwool publishes no weight for it, so we don't score weight
- Thin 150 g/m² fabric: independent reviewers expect it to wear thin or develop holes with hard use
- Slightly itchy until washed a few times, with noticeable seams at first (CleverHiker)
- Not warm enough alone for winter hills
- Merino is slow to dry
- Warm gentle wash, and a low tumble dry at most
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.
ShowHide sources (5)
- Smartwool UK: Men's Classic All-Season Merino Base Layer Crew (code sw016953, price, 88% merino, 12% nylon, no weight)
- Smartwool US: Men's Classic All-Season Merino Base Layer Crew (code sw016952; lightweight, 150 g/m²; no weight)
- Advnture: Smartwool Men's Classic All-Season Merino Base Layer Long Sleeve review (12 March 2024)
- Better Trail: Smartwool Classic All-Season Base Layer review (22 January 2026; comfort 4.5, odour 4.5, durability 2.5 of 5)
- CleverHiker: Smartwool Classic All-Season Base Layer review (17 October 2024)