Everything I know about glitter is wrong

I spent the better part of the past year writing a novel, in which (among other outlandish incidents) a troublemaking teen attempts to bake a cake with glitter instead of sugar. Now that the book is out, I got to thinking about glitter. What is it made of? When was it invented? Most important of all, what would happen if someone baked it into a cake and ate it?

I thought I knew glitter. I was so wrong.

It’s old. Very, very old.

I assumed that glitter was invented some time in the Victorian era, probably for the sole purpose of gaudying-up sentimental greeting cards. But glitter is much older than I ever guessed.

Some time around 40,000 B.C., ancient humans began dusting sparkly crushed minerals over their cave paintings. As early as the sixth century A.D., Mayans were adding glitter made of mica to their temple walls, according to National Geographic. And in 2010, the BBC reported that reflective material was discovered mixed in with what is believed to be the residue of 50,000-year-old Neanderthal cosmetics.

It’s not made of metal.

Aluminum, maybe tin: That’s what I thought glitter was made of. Nope. Modern glitter was invented in 1934 in New Jersey, of all places, when American machinist Henry Ruschmann figured out a way to grind plastic into glitter. Eventually the raw material evolved into polyester film layered with coloring and reflective material “fed through a rotary knife cutting system … kind of a combination of a paper shredder and a wood chipper,” according to glitter manufacturer Joe Coburn. Before that, glitter was made of glass. Not something you’d want to eat.

It’s everywhere.

Tons of glitter are produced every year (literally, tons). There are 20,000 types of glitter available from pioneer glitter-makers Meadowbrook Inventions alone, ranging from the run-of-the-mill craft glitter you remember from kindergarten to “special effects” glitter for industrial applications. It can be as fine as dust or as chunky as confetti. As glitter manufacturer Coburn remarked on Reddit in 2014, an order of “2 tons a month is a very small size … that $#%@ is everywhere. Just look closely at consumer goods. Some giant manufacturers in the states and East Asia/India sell a hundred tons or more a year.”

You can see a glitter-making machine in action here — it’s disturbingly efficient at reducing thin sheets of polyester film into gleaming little grains. Glitter isn’t biodegradable and most people don’t recycle it. So it’s not going anywhere.

You can eat it.

Hold on! You can’t eat just any glitter. It has to be edible glitter, a hip new condiment that gained fame on Instagram in 2017. Since the first twinkling photos showed up, it’s made an appearance on everything from donuts to bagels to pizza.

In the interest of serious academic research, I believe it’s essential that I investigate and consume edible glitter. What is it made of? When was it invented? Most important of all, what would happen if someone baked it into a cake and ate it?