Sei Sheet Set

The Sei Sheet Set is 100% cotton sateen woven at 600 thread count, the highest thread count MATTEO produces. We stop at 600 TC because going higher typically yields a stiff, dense fabric that does not breathe or move well. Thread count measures the density of the weave, but it does not account for the softness of the raw cotton or the balance of the yarn, which is why Sei is one of our purest, silkiest fabrics rather than simply our highest-numbered one.

Yes. The Sei Sheet Set is 100% cotton sateen at 600 thread count, garment-dyed and manufactured by MATTEO in Los Angeles, and it meets the density and weave construction used in high-end hotel bedding. The sateen weave produces a smooth, crisp face that mirrors the hotel-quality finish many people associate with a well-made bed. Interior designers and hospitality buyers have specified MATTEO luxury cotton bedding for exactly this reason.

A sateen weave floats more yarns across the fabric surface, which is what creates the characteristically smooth, silky face that sateen sheets are known for. Percale, by contrast, uses a one-over-one-under plain weave that produces a crisp, matte finish with a slightly lighter hand. Sei sits at the silkier end of the spectrum: the face of the fabric is notably smooth while the back carries a rougher texture, and the 600 thread count density gives it more body than a standard sateen.

Garment-dyeing means the finished sheet set is dyed as a complete product rather than dyeing the yarn or fabric beforehand. MATTEO uses reactive dyes in its Los Angeles dye house, and the result is a color that has depth and a lived-in quality from the start. Because garment-dyeing is an art rather than a precise science, we allow for a shade variation of plus or minus 10% from dye lot to dye lot. You can learn more about our garment-dyeing process here.

Machine wash in lukewarm water with a gentle detergent and a cool rinse, keeping light and dark colors separated. Tumble dry on low heat and remove the sheets promptly from the dryer to reduce wrinkling; line drying gives the best results. Do not use bleach or any products containing chlorine, alpha hydroxy acids, or benzoyl peroxide, as these whitening agents will break down the reactive dyes used in the garment-dyeing process.

The Sei Sheet Set is available in Twin, Twin XL, Full, Queen, King, and Cal King. Every set includes one fitted sheet, one flat sheet, and one or two pillowcases depending on your bed size: Queen and King sets include two pillowcases, while Twin and Twin XL sets include one. Buying the set saves 10% compared to purchasing each piece individually, and all items are garment-dyed together so they arrive as a matched set.

Yes, but you would need to order each piece separately to do so. When you purchase a Sei Sheet Set, all items are garment-dyed together in the same color, so the fitted sheet, flat sheet, and pillowcases will all match. The Sei collection is available in fifteen colors, including White, Off White, Greige, Mica, Coal, and Night, among others, so ordering individual pieces gives you full control over how you combine them.

Sei is 100% cotton with no synthetic fiber content, and MATTEO uses reactive dyes rather than enzyme softeners or chemical finishes to achieve its smooth hand. The sateen weave produces a naturally smooth surface against the skin, and there are no added softening agents that might cause irritation over time. For those who want cotton bedding without synthetic additives, the Sei Sheet Set is a straightforward choice, manufactured and garment-dyed by MATTEO in Los Angeles.