Mid-century plastic leaves: all of the autumn color, none of the raking.
Shop for mid-century costume jewelry for long and you'll run into the word thermoset: thermoset leaves, thermoset cabochons, a Lisner thermoset bracelet. It's the smooth, molded plastic of the 1950s and 1960s, set in gold-tone or silver-tone metal and made in every color from white to burnt orange. Here's what the word means, how collectors use it, who made it, and how to check and care for a piece.
Our signed Lisner white thermoset leaf bracelet is in the shop now for $30, and it's the only one we have.
See the bracelet →
What thermoset means
Plastics come in two families. A thermoplastic softens when it's heated, so it can be melted and shaped again. Lucite and other acrylics, celluloid and polystyrene are all thermoplastics. A thermoset is different. It is cured once, with heat, into its final shape, and after that it never melts again. Bakelite is the best-known thermoset.
How collectors use the word
In the jewelry trade, thermoset has come to mean something narrower: the opaque or pearly molded plastic pieces found in costume jewelry from the 1950s and 1960s. Think of leaves, petals, ovals and squares, each one molded with its own ridges and curves and fixed into a metal frame.
Here's the part most guides skip. Very few of these pieces have ever been tested, and nobody can say for certain which plastic each maker used. Some reference writers simply call them plastic or resin for that reason. So when a listing says thermoset, read it as the name of a style and an era, the same way the trade says Bakelite for a whole family of early plastics.
When it was made
Thermoset jewelry belongs to the 1950s and 1960s. Plastics were cheap, light and took color beautifully, and costume jewelry makers used them for matching sets: a necklace, a bracelet and clip earrings in a color to go with that season's dresses. It was made to be affordable. Lisner pieces sold for about $3 to $5 each when they were new.
Who made it
- Lisner: the name collectors think of first. Lisner used molded leaves and cabochons in vivid colors, and its oak leaf sets, made for about five years starting in the early 1960s, are its best-known line. Red oak leaf sets are among the most sought after.
- Coro: known for confetti Lucite and for moonglow, a plastic with a soft pearly sheen that came in many colors.
- Richelieu: its Iridelle and Satinore lines of the late 1940s came before moonglow and have a similar glow.
- Trifari: used plastic cabochons, leaves and beads in its 1950s and 1960s jewelry.
- Selro: known for molded faces and panels with an Asian theme.
Plenty of thermoset jewelry is unsigned, too. A piece doesn't need a name on it to be the real thing from the period.
A little about Lisner
Lisner was sold at a modest price, but the quality held up, which is why so much of it is still wearable today. In the mid-1970s the company bought the Richelieu Pearl Company and became Lisner-Richelieu. It was sold to Victoria Creations in 1979, and no Lisner jewelry has been made since the mid-1980s.
On a signed piece, look for the name on the clasp or the back. A copyright symbol next to it, written as © LISNER, tells you the piece was made after 1955, when American costume jewelry makers began marking their designs that way.
What it looks like
- Molded shapes: the detail is molded in, not carved by hand, so every leaf on a bracelet is a match for the others.
- Finish: glossy or soft satin. Most pieces are opaque, and some have the pearly inner glow collectors call moonglow.
- Color: white, pastels and strong brights, with the color running all the way through the plastic.
- Weight: light for its size, which makes even a wide bracelet comfortable to wear.
- Settings: the plastic pieces are usually glued into metal cups or frames, sometimes with small prongs as well.
Thermoset, Lucite or Bakelite?
- Bakelite: older, mostly from the 1930s and early 1940s. It is heavier, was carved and polished by hand, and gives off a sharp chemical smell under hot water. Our Bakelite guide covers the tests.
- Lucite: an acrylic that is usually see-through, either clear or dyed. Confetti Lucite has glitter or bits of shell set inside it.
- Thermoset: in the collector's sense, the opaque or pearly molded pieces of the 1950s and 1960s, set in metal.
Skip the hot water test on these pieces, since hot water can loosen old glue. And never use the hot pin test on any plastic jewelry. It leaves a permanent mark, and some early plastics burn easily.
See the difference in person: vintage plastics in the shop
Thermoset and its cousins side by side. Each one is a single piece, so when it's gone, it's gone.
What to check before you buy
- Yellowed glue: the glue under the plastic pieces often turns amber with age. Look at the back and at the edges of each piece. It is a cosmetic flaw, and a good listing will point it out.
- Loose or missing pieces: press each one gently. A matching replacement is hard to find, so a complete piece is worth more.
- Matching color: compare the pieces to each other. One that is a different shade may be a replacement.
- Scratches and scuffs: they show most on a glossy finish, so tilt the piece in the light.
- Metal and clasp: check for worn plating on the high points and make sure the clasp closes firmly.
Caring for thermoset jewelry
- Wipe it with a soft, barely damp cloth and dry it right away.
- Don't soak it. Water works its way under the plastic and loosens the glue.
- Keep it away from perfume, hairspray, rubbing alcohol, nail polish remover, jewelry cleaning dips and ultrasonic cleaners.
- Keep it out of heat and direct sun. A hot car or a sunny windowsill is no place to leave it.
- Store pieces flat and apart from each other so they don't scratch.
Thermoset in the shop
We have a Lisner white thermoset leaf bracelet in the shop now, with seven double leaf links in silver-tone metal and © LISNER on the clasp. More thermoset pieces are on the way, and we'll add them here as they're listed. You can also browse our vintage bracelets and the rest of the jewelry collection. Every piece is the only one we have.
Keep browsing:
Vintage bracelets →Mid-century jewelry →Signed designer jewelry →
Keep reading: What Is Bakelite? · What Is Lucite? · What Is Celluloid?
Did your mother or grandmother wear a matching set of plastic leaf jewelry? What color was it?