I use different brands and lines of polymer clay --sometimes mixed together-- depending on what I'm making (how strong or detailed, etc, it needs to be) and what I have around the house (a lot
of old clay).
In really hot weather especially or if I had hot hands, I'd probably go for one of the firmest clays though (Kato Polyclay
) or at least a blend of one of them with something else, since they're the "best" for nice handling, fine detail, etc.
I guess my "regular" clay has been Premo
in the past (soft enough for my hand/arm problems but still very good), but not sure about it now after all the clays had their latest reformulations. I'd probably mostly go for Kato these days especially if Premo weren't good enough, and Donna sells it pretty cheap at her site which is another benefit.
I haven't tried the newest Cernit,
but would be open to it for its vibrant and somewhat-translucent colors (or I'd add a bit of white to opaque the colors).
Cernit and Premo are somewhat heat senstitive, but I don't have hot hands and know not to work-and-work my clay without cooling it
The only times I've tried using FimoSoft
have been disasters. Don't know if I got a bunch of bad bars, but the stuff was just not "nice" to handle the way I'm used to, some of the colors came off everywhere, and I just couldn't make it behave the way I'm used to polymer clay behaving. It's also not as strong in thin areas as Kato, FimoClassic, Premo and Cernit.
As for the Sculpeys
(the Polyform clays), I have a bunch of leftovers of Sculpey III
(mostly from long ago) and have used it for certain things (just not things that required strength in thin or projecting areas unless mixed with other brands/lines). It's very soft and can't get the fine detail I want for some things, and distorts and gets fingerprints more easily.
(boxed) I do have around as my "bulk" clay for making all kinds of things I don't want to waste "colors" on...sometimes just samples, sometimes also to clean my pasta machine, etc. I also use SS to make molds from (but often tint batches of it with colored clays a bit so I can keep the categories of my molds easily recognizable in their boxes --e.g., green for faces and humans, burgundy for animals, blue for geometrics, purple for plants, etc.).
I also have original plain (boxed) Sculpey
around (in white), because there are a few ways I can use it too on occasion even with it's extreme brittleness in thin areas (even worse than the other 2) like bead cores and other armatures, for kids to play with without using up too much regular clay (can easily be tinted with oil paints if they want), or in one case to make "dividers" in a shallow box lid, etc. And of course, it's cheaper by volume than any other polymer clay and can even be purchased in larger amounts (5 lbs, 25 lbs, etc). (When sold in art supply stores, it's called Polyform
The softer clays like these Sculpeys can also be used as softener mix-ins for my harder and/or older clays.
I may also use or prefer certain brands for my translucents, glow-in-the-darks, the mica-containing metallic clays, "stone" colors, and some other specialty "colors" because they're better, or because they're not offered by the other brands.
I hadn't realized that the Studio by Sculpey
line was being discontinued, but it was created for Donna Dewberry's classe$ in making "items for the home" which I guess never went anywhere especially in this economy, and also had some problems (didn't stick well to itself or to glass/metal, no saturated or dark or translucent or special colors, can get sticky with handling, etc).
They also may have decided to put their energy into their new line Bake Shop Clay
clay when sold by Michaels.) That's being targeted even more than their other clays to kids... very very soft (so distorts/etc), can be sticky, only a few colors...but cheaper than the better brands of polymer clay.
They also put out Pluffy
recently, a "foamy" feeling clay that's probably their Ultralight
polymer clay line but in colors instead of white.
BTW, I should also mention Polyform's SuperSculpey-Firm
--especially for sculptors who just like to paint over their clay-- which is supposed to be very good and not brittle, but comes only in gray and in larger packets.