What Louis Vuitton's own fit words mean on a knit
Louis Vuitton writes the fit into the product copy, and the words are specific. The Cashmere Pullover and the Formal Half-Zip Sweater are both listed as regular fit. The Brushed Signature Pullover is described instead as a fitted shape with a mock neckline, which is a different garment behaviour: a fitted knit sits close through the chest and shoulders, while a regular-fit crewneck drops straight from the underarm to the hem. Louis Vuitton's own knitwear pages tell buyers to review the stated size and product measurements and to consider the intended fit rather than selecting by label alone, and they note that slim, straight, relaxed and oversized silhouettes interact differently with what you wear underneath. The practical consequence is that two LV sweaters in the same letter size can hang differently on the same body, so the fit word and the garment measurements have to be read together rather than either one alone.
Men's knitwear runs XS to 5L; women's knitwear runs on French sizes
The two size systems on the same site are not the same system. Men's Louis Vuitton knitwear is offered on letter sizes that run from XS, S, M, L and XL into 3L, 4L and 5L, so the block at the top of the range is longer than most ready-to-wear. Women's knitwear is cut on French sizing, and the product pages anchor it that way: the women's Monogram Mix Cashmere Crewneck states that the model wears a FR M. A men's M and a women's FR M are therefore two different garments with different chest, shoulder and body lengths. The men's 3L to 5L block exists to cover larger frames and is a normal part of the range rather than a special order. When two Louis Vuitton sweaters are being compared, compare the size system first and the letter second, because the letter is defined inside its own system.
The fibre blends, in the house's published numbers
Louis Vuitton publishes the composition of each knit, and the spread is wide. The Cashmere Pullover is 100% cashmere. The Formal Half-Zip Sweater is 60% wool, 30% silk and 10% cashmere. The Monogram Brushed Knit Sweater is 62% wool, 18% alpaca, 13% cashmere and 6% polyamide, and the Brushed Signature Pullover is 73% wool, 18% cashmere, 6% alpaca and 3% polyamide. The Monogram Mix Cashmere Crewneck sits at 80% wool and 20% cashmere. Alpaca adds loft and warmth for its weight; the silk in the half-zip gives that fine knit its dry, slightly crisp hand; and a single-digit polyamide content is a structural addition that helps a brushed or jacquard knit keep its shape instead of stretching out. The blend, more than the size letter, is what decides how a sweater feels after an hour of wear.
Care: dry clean, never wash
Every Louis Vuitton knit on the site carries the same core instruction: do not wash, do not bleach, do not tumble dry, iron at a maximum sole-plate temperature of 110°C, and use mild professional dry cleaning in hydrocarbons. The fuller versions add gentle dry cleaning, dry cleaning inside out in a net, and ironing inside out with a fabric in between. For a knit, that instruction set is describing the fibre: wool, cashmere and alpaca mat and felt when they are agitated in water, and the ribbed collar, cuffs and hem that give these sweaters their shape are the first parts to distort. Store them folded rather than on a hanger, because a hanging knit carries its own weight through the shoulder seams and grows at the shoulders over a season. If a knit looks tired after a long day, rest it flat for a day before wearing it again.