Every beginner thinks Halloween HTV needs high heat (it doesn't, and here's why yours is scorching)
You cranked your iron to cotton because the vinyl package said 'heat transfer.' That's why your jack-o'-lantern design looks melted. Here's the actual temp that works.
I watched my sister-in-law ruin three black tees in a row last October. Same problem every time: she set her iron to the cotton setting because the Siser packaging said 'cotton compatible,' and her spider web designs came out with these weird shiny burn marks around the edges. The vinyl stuck, sure, but it looked like someone took a blowtorch to it. Turns out the single biggest mistake people make with Halloween HTV is assuming higher heat equals better adhesion.
why 'cotton setting' doesn't mean what you think it means
Here's the thing nobody tells you: when HTV packaging says 'for cotton,' they mean the fabric you're pressing onto, not the heat level you should use. Cotton fabric can handle high heat without melting. Your vinyl cannot. Most standard HTV (the kind you're using for Halloween shirts and trick-or-treat bags) has an ideal application temperature between 305-320°F. Your iron's cotton setting? That's 400°F or higher.
I didn't figure this out until I bought a $9 infrared thermometer from Harbor Freight and actually measured my iron. The cotton setting on my ancient Black+Decker hit 425°F. The polyester setting sat right around 310°F. Suddenly every scorched project made sense.
the Halloween colors that scorch the fastest
Not all vinyl burns the same. Black, orange, and purple HTV (aka every Halloween design ever) are way more prone to heat damage than lighter colors. Black especially shows every flaw. You get shiny spots, a weird plasticky texture, or this raised edge effect where the vinyl looks like it's trying to peel itself off.
Glitter HTV is even worse. That topcoat is basically fine polyester glitter suspended in adhesive, and it melts at a lower temp than the base vinyl. I ruined a gorgeous orange glitter pumpkin last year by leaving my iron on it for 20 seconds at full cotton heat. The glitter turned into this sad, flat, shiny mess. Looked like I'd ironed a plastic grocery bag.
- Black HTV: scorches at 350°F+, shows every heat mark
- Orange glitter: top layer melts around 320°F, go low and slow
