I myself have in the past used Sculpey Glazes which come in Gloss Luster, Semi Gloss and and Matt. All work well for some creations and its air drying so you bake your items, sand them if you wish and then dip or brush on the Sculpey Glaze with the desired finish of choice. I recommend brushing on any sealer you use, as dipping items can cause large drips of sealer to build up on the ends and the result not only does not look very professional but those dried up blops of drips can more easily peal away from the item leaving it un-sealed and thus very unfinished in the long run. Many gloss finishes brushed on will leave brush marks if you do not use a good soft brush, but for those sealers you can put into the oven for a few moments at like 200 degrees (US) the heating will not only set the sealer on your piece but will eliminate any of those brush marks in most cases.
Now there are a few other products out on the market I have heard about using. Obviously everyone has heard of the "Future" Floor Polish. Its cheep for many and easily available for most people in most grocery store isles. Not if your me though, I couldn't find Future but found another product called Quick Shine and well I purchased it but only tried it out once and I really did not mind the finish but I really did not notice much of one either. It was the first time I was trying to seal something. The bottle is as large as the Future but sitting on a shelf collecting dust, at least until I do some more testing with the stuff at a later date.
Krylon Triple Thick is great stuff, not cheep though and it comes in a container much like cold cream would come in with a screw top lid. Thats if you can find the stuff. I have been to Pearl which is a major supplier of paints and glazes, glosses etc., and they did not have it. Told me to try Sherman Williams as they are the ones who create Krylon. You could use it right out of the original container or put some in a smaller container for quick and repetitive uses. Its a good idea to do that with any sealer you use often. Its easier to use in this manner you will find, clean up is easier to. Any unused portions can be kept in their original containers longer since your not opening and closing the containers constantly allowing air to get into it and eventually dry it out over time.
So since not being able to find Future, and not trusting the Quick Shine and not being able to yet find Triple Thick from Krylon, I just purchased from Michael's Crafts some Clear Gloss Glaze from Delta which is an Air-Dry PermEnamel (Says Step 3 on it) so I assume its a part of a few other steps for something, but I just got the 2 FL 0z plastic flip top jar. It says its for Glass, Ceramic & Tile. It says though that its not for surfaces with food, which I don't use polymer clay with food items anyway, but it says it cleans up with water and soap and takes 10 days to fully dry. I don't always have that kind of time to wait. But I do like the shine it gave the items I have sealed with it. Its small but only cost a few dollars. Not sure of the long term effects of what is coated with it.
Mod Podge. Yep the good ol' stuff for decoupage and other crafts that acts like a glue. If you ask me it is a watered down form of Elmer's white glue that dries clear. Which I have used with some success in the past for my Air-dry-clay like sculptures. I love the gloss shine it gives and I believe its water proof once dried completely but I have felt my beads felt a little magnetic like, as if there were sticking together. Oddly though they always pull apart with ease and no residue or any sign that they were sticking. Almost like static electricity was holding them as such. I used the one that is marked Gloss and has a dark orange label on the outside of it. Its cheep and you get allot for the money and it can be used for many other crafts as well as a sealer and or a glue.
Now many well known artists who create with polymer clay and who make allot of wearable art items are using MinWax Varathane.
Water Based Varathane Diamond Polyurethane Interior to be exact which is how the label might read. I am sure you can find it in any hardware store that sells paints and stains as well as possibly Wall-Mart which the one by me does have a paint department. I could go on and on and tell you about this wonderfully recommended product but I would much rather leave it to the wonderful Sarajane of Poly Clay Gallery as she has a wonderful write up about the stuff, her own use over many years and her own personal recommendation of it. Like anyone Sarajane has her opinion but she is regarded an expert in her craft working with polymer clay and her words to me are like reading the polymer clay bible. I trust what she says and would try anything she recommended. Her things are amazing and all look wonderful. Also she has an image up on her page about the varathane that shows you exactly what to look for when you go out to the store to get some of this great stuff.
If you have tried any of the sealers listed here and or others, please do write to me and or just leave a comment here to let us know what it is, what it does, and where you can get it. I would love for this to be a post allot of polymer clay and other clay artists can come and see for helpful and most useful information regarding the sealing of their artwork, making it permanent and safe to wear as well as kept nice for many years to come.