Years ago when I started making candles, the choice for wicks was nothing like it is today. And of course, the first wicks I used were zinc. Those darn wicks would mushroom to the size of an eraser on a pencil. Good grief, they were horrible now that I think back. I've come full circle because I'm with Grumpy on this one, zincs work fantastic in 4627 wax for me, and I use them for jars under 3" all the time and get a great melt pool and a strong scent throw and the mushrooms are not big like they were back then. It helps to buy them from a good supplier and I always buy from Peaks. They don't vary in quality and I know I can rely on Peaks for the quality. With that said, if I am making a candle that has an oil known to need a hotter wick, I'll always use the cotton wicks from Peaks. Again, for the quality. They don't mushroom like they used to either. There are so many variables in waxes, blends, the % of fragrance, etc, it's all about what works for you. When we tell you what we use, don't set it in stone for yourself. Test, test and test some more as everyone always says.