Women's Intraknit Thermal Merino Base Layer Colorblock 1/4 Zip

Intraknit™ technology is the family’s 3D-knit construction innovation — a single-piece knit that’s engineered with different knit structures in different zones of the garment rather than a single uniform knit across the entire surface. The 3D-knit construction builds mesh ventilation zones, stretch zones, and thermal zones into one continuous piece of fabric, eliminating the cut-and-sewn panels that a traditional base layer construction would use. The result is a base layer with no seams to chafe, no panels to bind, and no zones where the wrong knit structure creates a hot spot or a cold spot. (Note: this is the same Intraknit™ 3D-knit innovation used across the Intraknit Thermal sub-line — the SW016453 Men’s Intraknit Thermal Colorblock Crew, SW019284 Women’s Intraknit Thermal Colorblock Crew, SW016828 Men’s Intraknit Thermal Bottom, SW016829 Men’s Intraknit Thermal Bottom — all built on the same 3D-knit platform.)

The Intraknit™ Merino wool delivers moisture management, temperature control, and odor resistance — the three performance benefits Merino is known for. The 56% Merino content is balanced against a 44% Polyester component (the structural polyester the 3D-knit construction uses to create the different knit zones), keeping the Merino’s natural performance benefits front and center while the polyester delivers the structural stability the 3D-knit engineering requires. The 56% Merino is in the moderate-to-high range — higher than the SW019284 Women’s Intraknit Thermal Colorblock Crew (53% per prior extraction), similar to the SW016453 Men’s Intraknit Thermal Colorblock Crew.

The 3D-knit construction builds mesh ventilation zones into specific areas of the garment — the high-sweat zones (under the arms, across the upper back, along the sides) where the body’s heat output is highest. The mesh layers are knit directly into the 3D construction rather than added as separate panels, which means the breathability zones move with the body without binding or bunching. The breathability is positioned specifically for the high-output moments of cold-weather activity — the uphills, the high-intensity intervals, the chairlift-to-descent transitions — where the body’s heat output exceeds what a single-knit base layer can release.

The Intraknit™ construction is engineered to let you move more easily and freely — the 3D-knit’s targeted stretch zones (at the elbows, under the arms, across the shoulders) are knit into the construction at the articulation points where the body needs the most range of motion. The result is a base layer that moves with the body through reaching, swinging, and the high-output motion that winter activity demands, without the binding or restriction a less-engineered base layer would create at the shoulders or elbows. The 1/4 zip front allows additional venting during high-output moments and additional coverage during cold moments.

Striking colorblock patterns position this Intraknit as the lifestyle-friendly option in the sub-line — the colorblock construction means multiple colors are knit into the same garment in distinct zones (chest panels, sleeve panels, side panels, shoulder panels) rather than a single solid color across the entire surface. The colorblock construction is the response to the buyer who wants the technical performance of an Intraknit Thermal base layer with the aesthetic versatility to wear it as a standalone top in social settings (out with friends, running errands, the après-ski lodge) without the all-technical look a solid-color base layer would have.

The 1/4 zip front allows venting on the uphills and full coverage on the chairlift — the zipper pulls down for high-output climbs and back up for the cold chairlift ride or windy ridge walk. The 1/4 zip is the right tool for stop-and-go cold-weather activity where the body’s heat output fluctuates rapidly between the cold chairlift and the high-output descent. The 1/4 zip also makes the colorblock patterns visible across the chest and upper torso when worn open.

The fit is cut specifically for women’s body geometry — narrower through the shoulders, slimmer through the torso, shaped for a women’s bust and waist rather than a unisex cut that bunches or binds at the chest. The women’s-specific fit is the difference between a base layer that feels tailored and one that’s just sized-down from a men’s pattern. (Note: this is the same women’s-specific fit approach as the SW019284 Women’s Intraknit Thermal Colorblock Crew in this family.)

The 3D-knit construction is engineered to enhance performance — the targeted mesh ventilation zones release heat where the body needs it, the targeted stretch zones enable the body’s range of motion, and the targeted thermal zones retain warmth where the body needs it most. The performance construction is the difference between a base layer that responds to the body’s needs across the full range of cold-weather activity and a base layer that just sits there doing the same thing regardless of what the body is doing.

The Intraknit Colorblock 1/4 Zip is the foundation piece of a women’s cold-weather layering system — the first layer against the skin that the rest of the system builds on. Layer a Smartloft or Winterloft mid over it for the deep-winter cold, add a shell for wind and weather on the exposed lift line or the windy ridge, and the Intraknit’s 3D-knit handles the foundation moisture management and temperature regulation. The slim women’s-specific fit layers cleanly under any mid or shell without the bunching a boxier base layer would create.

The description’s positioning — “out with friends or just running your errands” — captures the dual-use nature of the Intraknit Colorblock. The base layer is technical enough to perform as a foundation layer under a shell on the slopes, but the colorblock construction and the 1/4 zip styling make it wearable as a standalone top in social settings where a technical-looking solid-color base layer would feel out of place. The dual-use positioning is what differentiates the Intraknit Colorblock from the more technical-looking solid-color Intraknit Thermals in the sub-line.

Intraknit™ 3D-Knit Innovation; 56% Merino Wool Moisture Management; Mesh Layers For Breathability In All The Right Places; Move More Easily And Freely; Colorblock Patterns Get You Noticed; 1/4 Zip Front For Vent Control; Women’s-Specific Fit; Performance Construction Enhances Activity; Layering Foundation For Cold-Weather Systems; Out With Friends Or Running Errands