Glove Warmth Is the Lining: Wool, Fleece, Primaloft and Thinsulate Compared

The shell blocks wind and takes the abrasion; the lining does the insulating. Two gloves with identical outer leather can be a season apart, and the entire gap sits inside the shell.

The lining materials

Insulation works by trapping air; the governing spec is mass per area in grams per square meter, read with thermal resistance in clo — one clo keeps a seated person comfortable at about 21 °C (70 °F).

Lining	Published data	When damp	Dexterity
Merino wool knit	Absorbs roughly 30% of its weight in moisture while still feeling dry	Keeps insulating, dries slowly	Good in thin knits
Polyester fleece	No clo rating on labels; loft-based	Dries fast, loses loft once saturated	Good
Primaloft Gold	0.92 clo per oz/yd², rated near 500–550 fill down	Hydrophobic, quick-drying	Good
Primaloft Silver / Black	0.79 clo (~450 fill) / 0.65 clo (~350 fill)	Same family, lower clo	Good
Thinsulate type U	0.9 clo at 40 g/m²; 1.5 at 100; 3.0 at 200	Fibers absorb under 1% of weight in water	Falls as g/m² rises

For warmth-to-weight, the engineered synthetics lead. PrimaLoft’s tiers run Gold at 0.92 clo, Silver at 0.79 and Black at 0.65 per ounce per square yard, quoted by outerwear makers as equivalent to 500–550, 450 and 350 fill-power down. 3M’s Thinsulate data sheets publish clo by basis weight — 0.9 at 40 g/m², 1.5 at 100, 3.0 at 200 — and note the fibers absorb less than 1% of their weight in water. Wool’s advantage is not the clo number but the wet behavior: it absorbs about 30% of its weight in moisture before feeling wet and keeps insulating while damp, at the cost of slow drying.

Thickness is the tax

The shell is sized to the hand, and the lining consumes the room inside it — a thin cashmere or silk liner alone can cost a quarter to half a size, which is why lined gloves pinch in an unlined size. Thickness also costs dexterity: 3M lists type U insulation at 0.4 cm thick at 40 g/m² and 2.1 cm at 200 g/m², and a 2 cm pad inside a fingertip is not a precision instrument. The usual escape is a thin liner glove under a mitten, or a convertible glove.

Touchscreen fingertips

Capacitive screens need a conductive touch, and wool, leather and polyester all insulate. Touchscreen gloves weave silver-coated thread, carbon fiber or conductive yarn into the thumb and index — sometimes the middle — and the implementation matters more than the label. Coated fingertips wear off with abrasion and washing; knit-in thread holds up. A glove with one conductive finger cannot pinch-zoom, and a thick glove with a small patch demands a firmer tap than a thin liner with full-fingertip coverage. The conductive zone is also a slightly thinner, less insulating spot on exactly the finger that gets coldest.

Wet hands

Dampness decides which lining survives the day. Wool keeps insulating while wet and keeps going for hours; the synthetics dry faster and hold their clo because the fibers barely absorb water; leather soaks, stiffens and takes longest to recover. A waterproof or coated shell keeps the lining dry; without one, the best lining is merely slow to fail. Carry a spare pair if the day involves slush.

Lining choice starts from the hand itself: glove sizing runs on two numbers, and the same measure-first logic covers hat sizing; how to read a spec sheet covers where these numbers appear.