It can get a bit hard if you use too much. I do one coat and let dry and see if another coat is needed. I use it from the bottle without thining it down. For me it depends on what I put it one as to how stiff I want it to get. I live in an isolated area of the Blue Ridge Mountains, North Carolina (USA) and it is hard to go down the Mt. for supplies.

There are so many uses for nail polish. I've used it like you said on jewelry, filled in chips and scratches on porcelain appliances and our cars not to mention small cuts on my fingers. Works better than a bandage if your working in the kitchen around water.

I haven't had any problem with discoloration and I've washed and dryed many garments without any problem. The fray Check type products had to be reapplied after a few washings. I have used colored nail polish on darker items.

I painted my sewing needles also but on the insert end and then they would not fit in the needle holder. The shaft is a much better place.