Sei Sham Single

The Sei Sham is woven from 100% cotton in a sateen weave at 600 thread count, which is the highest thread count MATTEO produces. We stop at 600 TC deliberately: counts above that typically yield a stiff, dense fabric that does not breathe or move well. Sei uses the same 120/2 Ne yarn in both warp and weft, which gives the face of the fabric its characteristic smooth, silky hand without sacrificing drape. Thread count measures weave density, not softness of the raw fiber or balance of the construction — so chasing a higher number would not improve the result.

A sham is more fitted than a pillowcase and uses a closure — in this case, an envelope closure — to hold the pillow insert firmly in place. A pillowcase loosely encases the pillow and is open on one side. Shams are generally chosen for a more finished, structured bed presentation, while pillowcases are the more practical everyday option. If you are dressing a bed that will be seen and styled, the Sei Sham's 1/2" micro-flange and double-stitch detail give the bed a considered, intentional look that interior designers tend to prefer.

The Sei Sham is available in Queen, King, and Euro sizes. Queen measures 20 x 30 inches (51 x 76 cm), King measures 20 x 36 inches (51 x 91 cm), and Euro measures 26 x 26 inches (66 x 66 cm). The envelope closure construction works across all three sizes to keep the pillow insert snug without slipping.

Wash the Sei Sham in lukewarm water with a gentle detergent and a cool rinse, separating light and dark colors. Do not overload the machine, as this stresses the long cotton fibers. Avoid any products containing chlorine bleach, alpha hydroxy acids, or benzoyl peroxide on garment-dyed pieces, since the reactive dyes used in our Los Angeles dye house are not resistant to whitening agents. Tumble dry on low heat and remove promptly to reduce wrinkling; line drying gives the best result. Learn more about our garment-dyeing process.

Garment-washing is done after the sham is fully constructed, not at the fiber or yarn stage. This process opens the cotton fibers and produces the softened, relaxed hand the fabric has from the first night you use it. Because garment-dyeing is an art and not a precise science, MATTEO allows for a shade variation of +/- 10% from dye-lot to dye-lot. This is true of all garment-dyed textiles and is something we are transparent about rather than something we try to engineer away. The result is a depth of color that flat-dyed fabrics cannot replicate.

The Sei Sham is designed and manufactured by MATTEO in Los Angeles using 100% cotton sateen at 600 thread count, the same construction standard applied across MATTEO's luxury cotton bedding line. The 1/2" micro-flange with contrasting white double-stitch detail and the fitted envelope closure give it the structured, tailored finish associated with well-dressed hotel beds. The reactive-dyed cotton holds color cleanly over repeated washing, which matters for maintaining a consistent look over time. Interior designers who work with MATTEO specify Sei for clients who want that same level of finish at home.

The Sei Sham Single Clearance is part of MATTEOX, our clearance program for samples that may carry minor visible variations including off-color shades, slight thread irregularities, or faded edges from the dyeing process. Because we make everything in Los Angeles, occasional imperfections happen, and MATTEOX is how we make those pieces available rather than discarding them. Products marked 50% to 70% off are eligible for a full refund or store credit; products marked 80% to 90% off are returnable for store credit only. A $10 restocking fee applies to all MATTEOX returns.

Sateen uses a weave structure where more yarn surface is exposed on the face of the fabric, which produces a smooth, slightly lustrous hand. Percale is a plain, one-over-one-under weave that yields a matte, crisp finish. Sei's 100% cotton sateen at 600 thread count sits at the richer, softer end of the cotton spectrum; MATTEO's percale bedding is the right choice if you prefer a crisper, more breathable feel. Neither is objectively superior — the difference is a matter of texture preference and sleeping style.