SHRINKY DINKS

[Diane B.]

Plus, I've learned that there is a difference between a nice toaster oven and the clay oven I bought from Hobby Lobby. I was fortunate enough to have a toaster oven that my mom had bought back in the 90s from JCPenney and so I use that instead because my clay oven does not have even heat distribution and isn't hot enough, either.

Actually, what you found out is that toaster ovens in general can vary widely!!! 
The cheapies can work well and more expensive ones can be cruddy --all depends.  Also the toaster ovens made nowadays tend to be a little different (and often "worse") than those made in the past, but again the exact single oven can make a difference.
Some toaster ovens are "self-cleaning" too and those can't be used for many things because of the very high spikes in temp.

The "clay ovens" that are sold at craft stores btw are just cheap toaster ovens made in the Far East at the request of Amaco, etc., which have a few changes to the markings on the dial, plus some "won't go higher" than a preset temp that's supposedly good for polymer clay or they may have a timer.  Those are a lot more expensive usually than simply buying a regular inexpensive toaster oven from a kitchen or hardware store, etc.

Often polymer clayers will have to do some experimenting to find out if a particular oven heats to the temp that's actually set on its dial (often not), and whether it has hot spots in the center area of the cavity (areas close to walls or coils will always be hot spots). 
If the overall temp is off, just setting the dial using a cheapie oven thermometer will be fine. 
If there are hot spots in the center of the cavity though where you'll be putting clay or probably shrink plastic too, that's a worse problem and can be a deal breaker if clay is not baked with an enclosed baking method or at least a partially-enclosed method (a tent of aluminum foil on top, etc) which I guess should work for shrink plastics too.

When I've bought toaster ovens for crafts before, I've asked to go plug one in (in their back room, etc) to check the actual temp and potential hot spots**.  That way I won't have to go home to check, and can exchange for another one right on the spot.  Sometimes it can take a few exchanges to get a good one unfortunately.

The very best oven to use for polymer clay or for anything really is a microwave-convection oven.  The microwave part isn't used though, just the forced-air convection bake mode.  Forced-air convection means that the regular heat will be blown all around the cavity of the oven which makes the temperature quite even everywhere.  (The "convection" feature on many toaster ovens these days isn't very good, and often doesn't even last.)

** There's info on how to do that, as well as much more info about various ovens and baking polymer clay (also using "enclosed" or partly-enclosed baking methods) on this page of my site if you want to check it out:
http://glassattic.com/polymer/baking.htm

HTH,
Diane B.

[Eliea]

25 minutes sounds way too long to me forbasic shrinking I put them in for 7 minutes total. I'd try again but with a different shrink plastic and shorter time. I also don't turn my oven on that high only to 350 at most.
I found it helpful to use an oven thermometer and watch it as my oven came up to temp. I learned my oven doesn't heat evenly and where to put the shrinks in the oven to make them shrink the best.
I personally wouldn't use silicone to bake them on as if tends to be pours and flexible. The shrinks come out hot and soft and could shift in removing them from the oven and could stick to the texture. Though that could make a fun experiment if you wanted to play with it. 

[Neurosylum]

Thanks, Diane, lots of hot spots happening in the front right side of my oven! I'll be posting my final product in the finished jewelry section!

[LadyLeitzen]

ok guys, i ran "stuck", "sticking", and "stick" searches on this topic, and couldn't find an answer...

i'm trying to make big bang theory stitch markers for my friends for christmas and bought my first shrink plastic today.
they shrank beautifully.
directions then said to press lightly for about 15 seconds after you pull them out, until they're cooled.
i don't think i should have done that, because the white paper stuck to one side of the shrinky, and then they all stuck to the brown paper. when i pulled them off, the outline went with it, so now i have rather adorable drawings on my paper, but not on my shrinkies.

how do you keep them from sticking to the paper you bake them on?

[Eliea]

ok guys, i ran "stuck", "sticking", and "stick" searches on this topic, and couldn't find an answer...

i'm trying to make big bang theory stitch markers for my friends for christmas and bought my first shrink plastic today.
they shrank beautifully.
directions then said to press lightly for about 15 seconds after you pull them out, until they're cooled.
i don't think i should have done that, because the white paper stuck to one side of the shrinky, and then they all stuck to the brown paper. when i pulled them off, the outline went with it, so now i have rather adorable drawings on my paper, but not on my shrinkies.

how do you keep them from sticking to the paper you bake them on?

That's why I use pyrex. They stick a little but once cooled come off without a problem and the ink side goes up when I bake.
I have used brown paper if the ink or pencil side is up but sometimes they just stick. so pyrex is easier for me.

[LadyLeitzen]

thanks i'll try that next time!

[Eliea]

thanks i'll try that next time!

Welcome!

[bowwowpet]

I'm making dog charms for them to wear on their collars using inkjet shrinky dinks My question is whats the best way to seal them to make them waterproof? Being on a collar they may get rained on or dipped in their water bowl. I've read embossing powder before shrinking and spray acrylic gloss, mod podge. I would think no to mod podge it being water based. I need soemthing that really seals it well any thoughts or suggestions? thanks

[Diane B.]

Many things used on shrink plastic (before shrinking) are already waterproof, or may be made that way because the plastic will often shrink around the colorants during heating and kind of encapsulate them in plastic.

If you have something that isn't water-resistant though, you could seal with anything that's clear, permanent, and generally water-based...water-based materials like acrylic paints and finishes, permanent white glues and decoupage mediums, etc, are permanent and waterproof/resistant after they dry but not permanent before they dry.  Non-permanent paints/inks/etc like watercolors, tempera/poster paints/etc and some of the inks would be the ones that don't become permanent after drying.  
Since shrink plastics are plastic, petroleum-solvent based finishes/paints probably wouldn't be recommended (those are the ones that must be cleaned up with paint thinner/etc).

The toughest clear water-based sealants would be clear "indoor" polyurethanes (hardware store--gloss, if you want that effect), and some of the cyanoacrylate floor polishes like Future (Pledge with Future Shine) or Mop 'N Glo, and even clear acrylic fingernail polish.  
Other things that will seal but won't be as tough for scratching or cloudiness from later humidity/etc, would be white glues/decoupage mediums, acrylic mediums (intended to mix into acrylic paints), clear embossing powders, and to some extent epoxy resins and epoxy glues.

You might want to check out some of the info and links on this page at my site to find out more about all those things though:
http://glassattic.com/polymer/MISC.htm > Melting, Shrinking Plastics >> Shrinking Plastics
http://glassattic.com/polymer/finishes.htm

[Onyxnox]

What kind of dogs are they?  If they are active, playful dogs, they may break the tags through use. 

I usually use acrylic sealer or Mod Podge.  Don't go too thick or it will dimple.