I tried using those for Formica chips… But they are messy hard to hold and make too big of a burn on the wood for me. I feel much safer using a stainless wire with wooden handles that I make for that purpose.
I can't remember if I posted this earlier, but years ago I was kind of mocked on another forum about burning fine lines on a slope with wires. (on the tops) I caught some grief from people indicating I was doing it the wrong way, just use sharpened formica instead. I described how the wires made a much finer and cleaner line, beautifully black and burnished from the smooth wire so the bottom of the burn mark was actually radiused and smoothly rounded. One gentleman guaranteed he could duplicate that by holding formica to the wood so I sent to him a finished top with lines friction burned by the wire, and a partially finished top of the same material he could mount on his lathe, finish turning and burn the lines. After a long time he wrote back saying he couldn't do it. That, plus my own experiments, tells me that although it is possible to use formica, it's not easy, and if successful, the quality of the line is not even close. But to each his own - formica or other burned lines might make some perfectly happy and that's great.
But the fine wire stepped method is right for me, even if it takes longer. I'm in no hurry! I shoud get the award for being the slowest turner in the south east. I chuckle at the top turning contests have, counting the time in just a few minutes. But take a detailed look at the results. I may take 30 minutes on one but this is a hobby, therepudic, rewarding, and can make a lot of people happy.
Another comment, I see this style of top everywhere now, on web sites, youtube, etc. But when I started making these over 20 years ago, I searched the web and my books and found none similar, most were quickly turned, chatter textured, colored with markers. no sanding, no finish. One guy even told me a top won't spin nicely unless it has a heavy mass at the rim. He was misinformed. A few years after I started posting pictures of some of mine on a couple of forums I started seeing others making similar ones. Of course I can't claim I started something since turning has been around for 3000 years, but maybe a few people were influenced, don't know.
Some from 2003.
However, I do occasionally make some with thicker rims, like this "tire tread" top, the tread made with a texturing tool. It spins fine. I should make some more like this - people keep wanting them but don't want to give away the only one like it yet!