There are many different types of modeling materials on the market. In order to chose the right one you must first decide what you're trying to achieve with this modeling experience. Are you simply providing a tactile experience with some soft squishy stuff, or do you want something permanent at the end of the day? With most modeling materials, it's one or the other, not both.

With little ones, it's best to give them the freedom to squish, roll, and smush as desired. Play-Doh by Hasbro is everyone's favorite, and mine. However, you'll quickly realize that the dough is really only nice and soft the first time it comes out of the container (don't you love that smell!) and it quickly looses its appeal after a few uses. You could try making your own. Combine 1c flour, 1c water, 1/2c salt, 2t Tartar, 2T oil, and a few drops of food coloring in a saucepan and heat up slowly until it forms a ball. Remove from pan and allow to cool. Knead thoroughly. The best thing about this clay is that you can make large batches and really let your child have some fun. This dough will keep for months in an airtight container in the fridge. You could also make an edible play dough with equal parts peanut butter and non-fat dry milk with a little squeeze of honey. It's delicious! None of these modeling experiences will yield any works of art for your mantle, but you'll have lots of fun exploring.

My next favorite is Model Magic by Crayola. It's super soft for little ones. It sticks to itself easily so it's easy to create cool characters. This stuff dries in 24 hours. I still have a dinosaur that my son made 9 years ago and it looks exactly the same, plus a little dust. The colors are great and don't fade. It's not cheap, but I highly recommend trying it at least once.

Another option for little ones is oil-based modeling clay. If the package says "never dries" or "permanently pliable" it's oil-based clay. The down side is that this clay can be quite hard until warmed up in your hands. With attention spans of about 15 seconds, most kids won't wait that long. The colors are great, and the clay will last indefinitely. If your child wants to keep his creation, display it on a ceramic tile to keep the oils from being absorbed into the surface of your coffee table. It will keep for a long time, but it isn't permanent. Don't ever try baking this kind of clay.

Polymer Clay is another favorite of mine. It is also oil-based, but you bake your creations to make them hard and permanent. You can safely use this clay with children ages 4 and up. This kind of clay is also a little stiff at first until warmed by the heat of your hands. There are two brands that you'll find in craft stores: FIMO and SCULPEY. I have no preference between the two except that Sculpey is usually cheaper. The kinds of things you'll make with Polymer Clay will be much smaller in scale, probably no thicker than 1" and no taller than 3". Have some diaper wipes handy to clean off any residue from hands and work surface when done. I recommend "Clay Characters for Kids" by Maureen Carlson as a good "how to" book for you and your child.

Air-Drying Clays are wonderful for older kids who want to create larger project such as wall art, figures, and vases. You won't find the array of colors with this kind of clay. It comes in terra cotta, grey, and white. The clay is paintable once dried. You can come pretty close to the look and feel of earthenware clay except that you can't fire this kind of clay. It's a little messy, almost like playing in the mud.

Earthenware Clay or Firing Clay is best left to the professionals. There is definitely a technique to working with this clay. There are limits as to what you can build; it has a tendency to droop, crack, and fall apart. Despite these challenges, it is the ultimate clay experience. Once you've gotten this clay under your fingernails and the smell of it on your skin, you'll be hooked. Look for classes in your area for kids and adults. Don't bother trying this at home unless you happen to have a full-fledged clay studio.