BLACK SKULL DOG SWEATER. Skull sweaters are handmade. All sweaters are handmade & may vary slightly in color & style. The Black & White Skull & Crossbones Dog Sweater sweater is hand-knit and 100% wool. The dyes come from plants and are natural. The sheep who provide the wool live great lives and are mostly free range. Because the natural wool is not treated with chemicals they are both warm and dogs love them. No electricity is used to knit these sweaters. Talk about eco friendly! 100% hand knit wool Made following fair trade guidelines. All sweaters are handmade & may vary slightly.