This is basically an informational post about finishes that can be used --and also shouldn't be used-- for polymer clay.
(It's mostly things I've written before, but by putting it all together here I can have a fairly comprehensive summary of info to refer quickly to when questions about various types of finish and their differences come up . . . there is just a bit of overlap between the 2 sections though).
There are a number of ways to get a glassy look
on polymer clay... each has its advantages and disadvantages.
Btw, no finish is necessary
on polymer clay since it's waterproof all by itself, and many clayers use no finish at all, or they "sand-and-buff" to get a glossy surface or just a beautiful sheen.
Liquid finishes can be used though to give a high gloss--or slight gloss, or no gloss, depending on choice-- to clay surfaces, or they can be used to seal various things onto the clay's surface to keep them from oxidizing or from falling off, etc. (...note that metallic powders like Pearl Ex won't need
a sealer unless they are not well
rubbed in or unless they'll get a lot of abraision in use).
quick summary of possible finishes:
One can simply apply a (water-based) liquid acrylic/plastic
finish to baked clay.
There are two most-commonly used liquid gloss finishes by clayers because they do a good job and are cheap by volume:
, which are clear finishes that are sold for sealing bare wood (the most-used brand is Rustoelum's Gloss Varathane
--used to be made by Flecto)
.....clear "floor polishes" (Johnson's Future
, now called Pledge With Future Shine, is the most-used but may be called by other names like Klear/etc outside the U.S.)
(there are other brands
of both those types though)
There are also finishes put out by the clay manufacturers:
...Polyform's Sculpey Glaze
, etc. (see bottom of this post for changes in Sculpey's finishes)
...Fimo's Special Lack
...they used to sell 4 versions of varnish --gloss/matte, water-based/alcohol-based (the alcohol-based gloss version was by far the most popular) ...they're hard to find now though, or no longer made? or only 1 version still available? which is a water-based one and not very good)
There are also other materials
that can be used to give a glassy shine:
....e.g., acrylic mediums
, clear embossing powders
, permanent "white glues"
thinned with water and "dimensional" white glues," 2-part epoxy resins
and 2-part epoxy glues
, etc-- but all those either require more work or won't be as strong.
The other main way to create a high gloss is to wet sand
a bit (at least 400 grit then 600 grit), then buff with an electric buffer
-buffing won't take the clay all the way up to a glassy
shine--only a sheen).
If one is sanding lots
of small roundish beads (without powders/leaf, etc. on their suface which would be abraided off), using a regular kiddie tumbler
can save a lot of time and wear and tear on the hands. There are other electric devices
that can be used instead of a tumbler too. Translucent clays
or liquid clays
(Translucent Liquid Sculpey, Kato Clear Medium, Fimo Decorating Gel) can also be used, then sanded/buffed
to give a glassy shine... but if you want them to actually be transparent as opposed to just translucent, a very thin
layer needs to be used (certain other techniques will also help with clarity).
(Some people use only one
of those techniques... some people use more than one
technique in the same piece --though in a certain order).
a few variables about using the possible finishes:
varies between liquids
..... e.g., Future is thin (so often more than one coat is necessary for real visual "depth", and will actually give a sheen rather than high gloss shine if it's applied while the clay is still warm
), whereas Varathane is thicker and with one coat can give a deep, thick shine (it can also be dipped into for even thicker glassy shine)
.... Sculpeys Glaze is really thick (and gloppy)
.... Fimo has 4 finishes; the "spirit"-based Gloss one is probably the best finish there is for polymer clay, but it's really expensive!
...... dimensional glazes/glues, clear embossing powders, and acrylic mediums are all much more scratchable than the Varathane/Future/Sculpey Glaze/Fimo's laquer mentioned, and sometimes are more susceptible to clouding from later humidity
......the Gloss Varathane
also has something called an "interpenetrating network"--IPN-- which makes it bond down into the surface of the clay better than most other wood finishes and other finishes, plus it's UV resistant
........not all brands of wood finish are the same in other ways too (compared to Minwax, Golden, and/or others)... e.g., Varathane is very strong/unscratchable, doesn't "require ventilation" when applying, is less resistant to humidity while drying and afterward, has UV protection, etc
is less permanent than Varathane ...it's actually soluble in water if exposed to a lot of it, even after drying and rebaking; humidity can also penetrate Future if in long contact, turning the finish cloudy & sticky... also "immediate" solvents for Future are alcohol and ammonia, but even later products with ammonia can cause problems (some hair prod's, perfumes, etc.) ...Future is not UV resistant, though most clayers don't see problems with yellowing from UV exposure at least partly because of where we use it....Future will also peel off more easily if not applied and baked correctly
.....(polyurethanes-Varathane and floor polishes-Future can be "re-baked" 5-15 min
at 200-250 F to "harden" them and increase adhesion even more)
..... most water-based finishes will dry fairly quickly (but may not fully "cure" for a week), whereas epoxy resins take 24 hrs. to cure (for each layer, if there is more than one)... some water-based ones will take longer than others though because they're more responsive to humidity, temp, etc.
...... 2-pt epoxy resins (and epoxy glues) are less good for lungs than the acrylics we use and require at least some ventilation (...though they're still better than polyester resins --Castin'Craft, etc-- which require a lot of ventilation, and which won't work well as final
......2-pt epoxies do give an extremely glassy shine though, whether they're brushed on, poured into clay cells, etc.
...... some of these can't or shouldn't be heated (may bubble or yellow)... whereas some can be reheated, and will become even "harder" (but can't be heated for a long
time at a higher
...sanding and buffing
........sanding and buffing in the most common way we use for baked poymer clay is generally a bit more work, but it really doesn't take much time per piece
(lots of small beads, etc, will be a problem though)
...various different kinds of equipment and various supplies can be used to sand and buff to make things easier, including tumblers, but also some other quite unusual equipment/materials
...sanding (and buffing) are sometimes followed by clear liquid finishes, and the finishes themselves can also be sanded and buffed
alot more info on all these things and more on these pages:Finishes
(all the liquids mentioned --plus some "waxes" though those won't give a glassy shine)http://www.glassattic.com/polymer/finishes.htmSanding & Tumble-Sandinghttp://www.glassattic.com/polymer/sanding_tumbling.htmBuffing & Tumbling-Buffinghttp://www.glassattic.com/polymer/buffing.htm
....also using a rotary tool (Dremel)
for buffing and/or "sanding"http://www.glassattic.com/polymer/tools_Dremels_worksurfaces.htm
(...click on Sanding or Buffing, under "Dremels"...)Translucent Clayhttp://www.glassattic.com/polymer/translucents-glow.htm
(...click especially on Clearest Results...)Liquid Clayhttp://www.glassattic.com/polymer/LiquidSculpey.htm
(... click on Finish...)
more info --some overlap with above
Only one brand
of polymer clay actually has a natural "sheen"
after baking --(Kato
The other brands naturally have a matte finish (Sculpey is the matte-est, with Premo and Fimo being in-between Kato and Sculpey).Any clay
can be given a sheen though right on up to a very high gloss shine though, in several ways:WATER-BASED FINISHES
(some are much cheaper
floor polish, Mop 'N Glo (cyanoacrylates)
(thin... will give a sheen
if applied while the clay is still warm
from the oven, or will give a gloss
shine if applied when cool... sometimes several coats are used for very high gloss
, drying between each coat)
--clear acrylic finishes for bare wood like Varathane
(thicker... the Gloss version will give a glossy finish whether applied to warm or cool clay... multiple coats can be used, or the item can be dipped for a very thick high gloss shine... there is also a Semi-Gloss and a Satin in the water-based line, both of which are fairly matte; the Gloss can be made more matte though in various way)
--clear fingernail polish (the acrylic type, not "enamel")
--special "glazes" made for polymer clay
--the old original verion very thick and gloppy (clear in a jar)
.....the new Sculpey Glaze
is probably an IPN polyurethane like Varathane (Gloss or Satin), as is the Studio by Sculpey finish (Gloss only?)
has Gloss alcohol-based finish which is really nice but very expensive (and now discontinued probably)
is not as tough as polyurethanes and Future-Pledge above and may get scratches)polyurethane/acrylic SPRAYS
sprays can be used to to seal and/or give a bit of gloss, but they must not have a petroleum-based
solvent in their propellant because those materials will begin to dissolve the clay over time (can take months to show up) and make it sticky... sometimes heating or recoating with a pure acrylic then heating can help that, sometimes not... sprays also should be applied lightly,
in several coats
drying between each... probably won't give as even a coat as if brushed-on or dipped
--several brands that seem ok re propellant (some are gloss, some matte) on clay are Varathane spray (Gloss), some of the Krylons like it's Acrylic Matte Fixative, Plaid's Clear Acrylic Sealer (gloss), and Patricia Nimrock's Acrylic Matte Sealer, al though regular liquid finishes can also be applied with atomizers, etc
--other things like clear embossing powder
or 2-part epoxy resins
and other things
can be used... but they're either more difficult to use (resins), or don't give as good a result
For more info on all those, check out this page:http://www.glassattic.com/polymer/finishes.htmSANDING + BUFFING
--baked clay can be sanded a bit with (black, wet-dry) sandpaper
(and a little water
to keep any dust down and to keep the sandpaper clean) ...the grits usually used are 400, then 600
, but a few clayers go much higher.... be sure not to skip
grits though if you go higher
... if the clay is then rubbed briskly on fabric
(jeans, bedspread, towel, etc.), it will get a nice "sheen" on the surface
....if the clay is instead buffed with an electric buffer
(using a fabric buffing wheel), it will get a nice sheen
on the surface if buffed for a short time... but if buffed for a longer time, it will get a glossier and glossier
(...some people like to sand and buff, then apply a liquid finish as well
For more info on sanding and buffing, check out these pages:http://www.glassattic.com/polymer/sanding_tumbling.htmhttp://www.glassattic.com/polymer/buffing.htmPASTE WAXES
Some (though not many) clayers use a clear wax like carnauba or shoe wax to give their smoothed or sanded clay a bit of sheen
... then it's buffed after application.