Well after a few months of a hiatus I am back and writing up a tutorial for sculpting bases. I've been asked many times how I sculpted them so I decided to stop being a snob and show you ;).
First of all let me advise you. The method I am going to show you is a reduced cost but yet effective way to do this. You're going to spend a few hours and money doing this and you will need to know how to work with hazardous chemicals at a certain point. So if you feel this is too much then you are better off buying from great sellers like www.dragonforge.com.
OK let's get started. You will first need the following tools to make your sculpting blanks. Alternatively if you know someone with a lazer cutter they can cut more precise 30mm, 40mm and 50mm round base blanks and then you can mold them(which is what I did) but like I said this is a more cost effective method.
So let me list off the materials(from left to right):
1. Circle template: you can use a template or make one out of white sheet styrene and a circle cutter. Use .30" or .40" for easier cutting.
2. Basic Sculpting tool: I got mine from Games Workshop. Privateer Press has the same one.
3. Bases: more for checking accuracy so it's not required if you're a math wiz and can convert millimeters to inches.
4. Sculpy or Fimo: I used Fimo for this exercise. Alternatively Green Stuff would work also since it cures and can act like a mold.
5. Roller: The most precise one is the pasta clay roller machine since it provides consistency. But if you don't have a problem sanding your blanks after, then use this.
6. Dental plaster: for casting blanks. Not pictured but more on this later :)
First you roll out your Fimo or green stuff to a thickness of about a 3mm thickness or .12 inches. If you use a surface like plexiglass you can easily flip the Fimo around and roll the opposite side without damaging the front. Another reason why I love Fimo
Next place the circle template with the correct diameter that you want on top of the Fimo and use your sculpting tool to cut and remove the Fimo from the inside diameter of the template.
With the the template still on the clay, take the blunt side of your sculpting tool(see photos above so you know what I am talking about) and wet the end of the tool with water and smooth the inside edges of the clay so you can have the most precise circle you can get. Just keep scraping around in circles till it's smooth and perfectly even. If the clay starts to tear or break, you can always add more Fimo and smooth it out.
After all that, this is what you end up with. This is basically going to be your mold for your sculpting blanks. The next thing you do is pour some plaster into your "mold" to cast your blank. Wait about 5 -10 minutes after you notice the plaster starting to dry at the top and use the blunt end of a knife to scrape and smooth out the top surface of your cast. Don't worry about the plaster leaking out. If you rolled and flatten the Fimo with the rolling pin, it should hold the plaster with no problems. Now lets chat about plaster. I've had tremendous success with Merlin's Magic dental plaster, and I should for the money I spent on it :). But a good alternative is Hydrostone. It is strong but easy to sculpt with and cheaper and easily available. Just Google it for more info. Don't use Hydrocal or that stuff you find at model train shops. It's no good and will only make you angry ;). This is probably the most trial and error part of this process.
Now here's the kicker. With uncured Fimo, you will only be able to use it once to cast with plaster. To make more blanks you'll need to go through the process again and you will risk losing consistency with your blanks. I recommend you sculpt and cast your different size blanks and then sand them to consistency with each other and then use RTV silicone to mold them. Smooth-on products makes a good and relatively inexpensive 1:1 RTV silicone named Oomoo 30. Easy to use and cures in 6 hours.
Did I mention this was an investment?
After all that, this basically what you are going for. A nice blank round cast of your base. So now comes the sculpting part.
Since your blank will be relatively smooth, you can actually take a pen and draw your sculpting lines directly on the surface. To get that nice consistency within all your bases, I recommend using a template made on a CAD program. You can then use transfer paper and copy your pattern on to your blanks. Since I am so nice I will provide the template I used at the end of this article. So I hope I gave enough information to get you started. So hopefully within the next few days I can get the sculpting portion posted.
Like always, Keep on gaming!