How can you tell if a button is lucite?
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Lucite is the queen of diversity, appearing in many forms, colors and styles in jewelry from the 1940's on, although it was most popular during the '40's and '50's. It is an acrylic resin, and one type of thermoset plastic (Bakelite is another, although Bakelite is a phenol formaldehye resin). A brief aside here to clear up a point - the term 'thermoset' does NOT refer to a specific form or style of plastic; it is a broad-based term referring to any plastic that, once heated and formed, cannot be melted down and reformed.
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Posted at 4:30 am May 18, 2008 EDT
Great site with a TON of info, such as:
IDENTIFYING AND TESTING for MATERIALS:
Many button materials resemble other materials. There are many factors to consider when identifying materials, including: style, design, construction, shanks, color, luminosity, surface appearance (i.e. crazing, mold/saw/carve marks, unpolished inner surfaces as inside the self-shanks), etc. However, for some materials, to be certain, the hot needle test is necessary. Hot needle testing is not everyone’s cup of tea, and that is fine. If you decide that you want to identify materials yourself in this manner, here are some suggestions worth considering:
1. An electric hot needle gives the most reliable results because it has a consistent temperature that is hot enough to test all materials that can be so tested.
2. Any test should be performed in as discreet a manner as possible, so as not to leave a blemish on the button. This means that you should use the finest needle tip possible and touch it to an area that is the least visible. Normally this will be on the back of the button, under or as near to the shank as possible, but could be in a crevice or other hidden area. Do not test transparent materials if the mark can be seen through to the front. Try not to make more than one test mark, and use the same spot if a retest is necessary.
3. It is a good idea to practice testing the different materials using known examples of “junkers” to get used to the hot needle results.
4. Here are some materials that can be tested with a hot needle and the odor you can expect. More detailed information on testing plastics is available in the NBS Handbook on Synthetic Polymers.
Horn – cooking meat or burning feathers
Amber – pitch/resin Jet – coal gas
Bakelite – formaldehyde/carbolic acid Lucite – nail polish remover Casein – burned milk Rubber – burning rubber/sulfur Celluloid – camphor Tortoise-Shell – stagnant salt water
Composition – shellac/lacquer Vegetable Ivory – burning walnut shells
Gutta Percha – faint rubber but less acrid Wood – burning wood
Some people use various different chemical products to test for Bakelite. While these products may not be harmful to Bakelite if the button is immediately and thoroughly cleaned and dried, they can do damage to many other plastics. A test popular with some collectors involves dunking the button in very hot water to get an odor. We do not recommend either the chemical or hot water test, as they can damage some buttons being tested.
There are other ways to determine a material, such as the following basic tips:
1. Glass and stone will feel colder on the cheek than other materials. To determine between plastic, glass, china or stone: click on your teeth. Plastic will give a duller sound than the harder materials. You can also use the tooth test to determine between cold plastic enamel finish and true enameled metals; just be sure to click on the enameled surface, and not the metal.
2. A magnifying glass, preferably 10x, is indispensable in determining many materials. Between bone and ivory, look for tiny black specks in bone, where the blood traveled, whereas ivory will be finer grained and often show undulating or crosshatch lines. Usually, the workmanship on ivory is finer than on bone.
3. Composition has been erroneously overused to cover various different molded materials. The term "composition" should be used for only those buttons molded of shellac or comparable binders that are filled with ground minerals, plant matter, etc. Surface impression inlays of pearl tesserae and metallic flecks are often found on composition buttons.
4. It is sometimes difficult to tell between glass and china or porcelain. Look at the backs. China will show a more granular or pockmarked back surface where it rested in the kiln. Porcelain may have unglazed portions on the back. Glass was molten when made into buttons, so will have a smooth surface on the back, and may show some mold marks. Old glass may have some slight surface “wrinkles” which occurred during the molding process, and are not defects.
5. Horn buttons may have a small hole gouged in the back of the button where it was picked out of the mold, called a “pick mark”. That’s just one way to tell horn. Some molded horn buttons have interesting backmarks, often French. A city in France -- Caen -- is often named. Another way to tell horn is to hold it to a very strong light. Many times you will be able to see the translucence of the material near the edge or in thinner places, even though it looks opaque black when not held to the light. The backs of some horn buttons show layering or flaking like old splintery wood. Most of these hints apply to the dyed (usually black) molded horn buttons. Besides black, horn can be found in blond, as well as dyed red, green, blue, etc. Natural horn is unprocessed and cut and carved from the horn tips.
6. A drop of water on the surface of jade will not spread out, but may draw in instead. However, on glass the drop of water will spread out.
7. True jet buttons are very rare. It is not unusual to see black glass being called jet, so don’t fall into this trap. Jet is fossilized coal, and is carved – not molded. You may see individual carving marks. They usually have a self-shank. It may have a glossy surface if polished. If chipped, you will see a conchoidal fracture. You may scrape the back of the button with a knife and get a very fine black powder.
8. Older pewter contains lead and will leave a pencil-like mark when drawn across a piece of paper. Steel will be attracted to a magnet. The back of the button may be japanned tin, which will also be attracted to a magnet. Be careful when testing with a magnet that you’re not getting results from the back of the button when the front may not be steel. Metal buttons are usually classified by the material on the front when it is 2 or 3-pc construction.
9. Hard rubber buttons are backmarked Goodyear, N.R.C., I.R.C.C., D.H.R.Co, or A.R.Co. and are usually black or dark brown, with tan and orange being scarce and desirable.
10. Vegetable ivory is made from the Corozo (also called Tagua) nut. Since dye won’t penetrate deeper than the outside layer, the natural creamy color can be seen in the sewing holes unless the button was dyed after cutting the holes. With good magnification, vegetable ivory will show an overall grid of tiny dots, particularly on the back of the button where it is less finished.
11. Wood buttons are made from natural wood, or they can be pressed or molded wood, such as Syrocco, Burwood, ANN or GAP types. The wood fibers in the pressed wood buttons should be visible under a magnifying glass.
12. “Plastic” refers to all semi-synthetic (celluloid, cellulose acetate and casein), and synthetic (phenolic, amino, polyester, acrylic resins, polystyrene, nylon, polyclays, ABS, etc.) polymers. If you are interested in learning more about these buttons, study the synthetic polymers glossary in the NBS classification booklet. National also has available for a modest fee a "Synthetic Polymers Handbook" that will give you much more information to aid in your identification efforts and general plastics education. Look on the inside back cover of your NBS bulletins for ordering information.
Posted at 4:37 am May 18, 2008 EDT
No problem...it helped me ALOT when I first started out.
While I am not an "expert", I do have some knowledge on vintage buttons and a lot of my business either sells (vintage/antique) or uses (hand altered) buttons.
LOL! You should SEE my inventory... ;)
If you ever have any ?, please feel free to convo me and I can try to be of help.
Posted at 4:53 am May 18, 2008 EDT
When I first started, I was unsure of how to categorize my buttons also, so I just kind of seperated them by color.
When I became a little more knowledgeable (did I spell that right?) I went back through them and re-did them. Boy, I was really surprised to see what I actually had in terms of "good stuff" when I did this!
Posted at 4:56 am May 18, 2008 EDT