Slytherin House Crest Halloween Costume Iron-On Patch

Slytherin is the crest that rewards a dark garment. The serpent design carries its own outline, so on black denim, a charcoal hoodie or a dark robe it holds its shape instead of dissolving into the fabric the way a lighter crest can. Single embroidered patch, roughly 3.5 by 4 inches, iron-on backing.

Size-wise it is a little wider than a credit card and nearly twice the height — substantial enough to anchor a chest panel or a backpack front, without spilling over onto a sleeve.

Where it holds

Cotton, cotton blends, denim and canvas all take the adhesive well. Heavy denim is the easiest surface of the lot: it takes the heat, it does not shift under the iron, and the bond lasts. Costume robes vary enormously — a cotton robe is fine, a cheap synthetic one is not.

Where it does not

Do not iron onto nylon, coated or waterproof shells, leather, faux leather or vinyl. They scorch or melt before the adhesive reaches temperature. The same goes for anything already carrying a printed graphic. On polyester, drop the iron a setting, use a pressing cloth, and test a hidden seam before committing.

Getting a clean press

Iron the garment flat first. Place the crest, lay a thin cotton cloth over it, then press down hard with a dry iron and hold — steady pressure matters more than time, and steam works against you. Leave it alone until it is completely cool. For a jacket that gets worn hard, stitch the border afterwards; treat the adhesive as the thing that holds the patch still while you sew.

Keeping it on

Inside out, cold gentle cycle, low tumble or line dry. Bleach and fabric softener both attack the bond. If the garment needs pressing later, iron it from the reverse side, never across the patch face.

Questions we get

Does it show up on black? Yes — that is the case for this one specifically. The crest carries its own border.

Sold as a set with the other houses? Yes — the four-house set bundles all four for $39.99. Singles stay available if you only want this one.

Is it strong enough for a costume that gets one night of hard wear? Ironed on, easily. If the costume is going in a box and coming out again next year, sew it.

See all four house crests, or read iron-on vs sew-on if you are undecided.