I have never worked with polymer clay before and made something small out of Fimo. ... Honestly, having never worked with clay it is close to a miracle that it even turned out semi-decent! Ignore the quality please -
Hey, very good job! . . . and
especially for a first timer!
(there are helpful tips for working with this medium that can help speed up a beginner's learning curve too

)
After I finished and baked it, I realized that I should have added deeper grooves between the ears and head so that the soap colors don't run. If the groove is deeper, I think that it will contain the colors better in the mold. ...Am I stuck? ... Is there a way to use a dremel or something to make the grooves more pronounced? Also, maybe I need to smooth the piece a bit because you can see some bumps and other marks. I'm guessing that I can't smooth it or change it....
The good news is that polymer clay
can be changed in various ways after baking... some might be more trouble to do, but they're possible. Polymer clay isn't actually all that hard after it's baked so it can be carved, drilled, sanded, buffed, etc, and new clay can be added to it in certain ways.
(see links below for more specifics on each thing I'll mention) First, the grooves. Btw, if you had used Sculpey III (or original Sculpey, or SuperSculpey-flesh), carving could sometimes be more difficult to do evenly because those lines of polymer clay are more "brittle" after baking (and if they're thin, that brittleness really shows up and makes them more breakable too). Fimo and the other brands will be less brittle after baking and have a "softer" baked surface.
So to deepen the grooves, you can just use a Dremel bit to carve them out more... use whichever bit seems to work best and most smoothly (try out on practice baked clay). Not sure how well you could
control the bit though.
The other option though is to reheat the clay to soften it a bit (say, 5 minutes at 200-250? F, for just the surface areas). Then you can use a U or V "gouge" or another tool to recarve them... if the clay gets cool, just pop it back in the oven again.
For the bumpiness (and for removing color from areas where the unwanted color is just on the surface), you can
wet-sand the clay (using wet-dry sandpaper that's wet). For actually "removing" clay, start with about a 320 grit. When you've got the surface down pretty even, then sand with 400 and even 600 to make it even smoother.
That will leave whitish areas on darker colors when the clay is dry... to get rid of those, either put the clay piece back in the oven a few minutes (perhaps coated with Softener-Diluent or even a bit of Vaseline or veg. oil) and the surface will soften back down to smooth. Or you can buff instead (hand-buff with a towel or other fabric to get a sheen... or use an electric buffer, even a Dremel with its buffing wheel if you use a light-moving touch, to get a sheen or all the way up to a high gloss shine).
Getting sandpaper (or sanding sponges, etc.) down into dimensional areas could be fiddly though. If that's too much trouble, you may just want to start again to save time.
This time though,
begin each section of clay with a
smooth ball (or a log or a sheet) of clay which has been well conditioned so that you can just
keep that smooth surface more easily.
If you still end up with areas of roughness or bumpiness before baking, you can also "sand" or partly "dissolve" the clay on the surface to make it smoother, with things like wet Bon Ami or Diluent, etc. things.
When incising lines into raw polymer clay as for your forehead and mouth, it's better if you can instead
impress something that's the right size-shape rather than drag a tool. Bits of bent wire/paperclip or the edge of various items are a few possibilities for "stamping" into clay like that.
If you do need to "drag" thickish lines though, use a stiff and smooth rod of some kind that doesn't have a sharp point (e.g. a tapestry needle or knitting needle), and pull the tool
toward you at an
angle, trying to press down the new clay at the leading edge at the same time... you may want to wet the tool or put cornstarch on it (possibly depending on clay brand) with each new pass. You can also drag your tools through the clay
over a piece of plastic wrap, etc, to create smooth lines. I wrote about this here in a message once... will see if I can find it. You can also use sharper-pointed things like pins when trying to carve tiny lines (as with faux scrimshaw, e.g.).
in addition to the above colors mixed a bit.
When you say they "mixed" a bit, do you mean while sculpting? For example, that one color transferred onto another (probably-lighter) color, or that the edge of one color got somewhere you didn't want it? For the former situation, you can sand off that color (and see the other tips in links below). Making each piece separately and very smooth can help keep the second thing from happening. Those things wouldn't matter for just making a mold from the item though.
I will eventually be using it to create a soap mold. . . .!
Were you thinking of making a mold from polymer clay for pouring soap into? If so, that generally won't work. What you'd want instead is a very smooth and flexible mold.
A two-part silicone putty would work very well but if your clay item is large, it would be kinda expensive unless you wanted to make a lot of soap casts from that mold.
There are also latex mold materials, etc., that are painted on a surface in multiple coats, but I don't know too much about those. Others at Craftster will probably know about materials for making soap molds though, especially if you put "soap" in the subject line, or ask in another board.
I've never made a mold either...but hey, that's for another thread!
Sure! You might want to check out the page linked to below about making polymer clay molds, and making molds from various materials to use with polymer clay too.
I have an online polymer clay "encyclopedia" so there are many more details about the things I've mentioned above there, if you want to check them out:
conditioning clay
http://www.glassattic.com/polymer/Conditioning.htm carving & gouges, etc
http://www.glassattic.com/polymer/carving.htm> Baked Clay
> Tools for Carving
sanding http://www.glassattic.com/polymer/sanding_tumbling.htm > Smoothing
Before Sanding --before baking
> Sandpapers
> Sanding
sculpting http://www.glassattic.com/polymer/sculpture.htm > Fingerprints & Smoothing
> Websites >> Whimsical
"stamping" into clay??
http://www.glassattic.com/polymer/stamping.htmmolds http://www.glassattic.com/polymer/molds.htmHTH,
Diane B.