How do you get the hard spot off a blanket after you spilled nail polish on it?

nail polish remover could be used, but it is going to thin the polish out as it dissolves it and it will spread into a bigger yet lighter stain. To try to avoid this, I would soak the nail polish stain as well as a decent size area around the stain with nail polish remover. As soon as the nail polish dissolves, which may take some gentle scrubbing with a brush, I would flush the area with running water. Once wet I would apply an adequate amount of industrial hand cleaner such as Goop, to break down the solvents of the polish and remover, then rinse in water again. I've seen this method used on a pair of white linen pants and it worked great. The results will depend on the type of fabric the blanket is made of and it could ruin the blanket altogether depending on the fabric. I would try a small amount of the polish remover on perhaps a corner of the blanket first to see if it attacks the fabric or any dyes in the fabric.