here is a good recipie. its the only one i use :)
There's a lot of recipes around for modeling chocolate, but here's mine:
A NOTE: all brands of white chocolate are DIFFERENT. You may need to adjust the amount of corn syrup you add depending on what chocolate you use and your personal preference. My recipe works perfectly with Guittard White Satin Ribbon, which unfortunately, isn't that easy to find. Do NOT use white chocolate chips!!! Pistoles or disks are fine. Or chop up a bar.
3 lbs white chocolate (broken into small pieces, if not already)
1 1/3 cup light corn syrup
Put chocolate into large round plastic microwave safe bowl.
Melt in short time increments of about 2 minutes and stir very well between each increment. White chocolate burns VERY EASILY. If your microwave has adjustable power levels and you have a high wattage microwave, you might want to use 50% power. I do, because I have one of those microwaves. You want to just melt the chocolate with no graininess or lumps. Make sure you stir it well to let any residual heat melt the chocolate, rather than keep sticking it back in the micro. That's a sure way to burn it. If you notice that your white chocolate starts feel thicker, then you've already burned it. I cannot stress how careful you need to be when melting white chocolate. Microwave a little at a time and stir stir stir.
When it's all perfectly melted, stick your corn syrup in the micro for about 1 minute to warm it.
Now, using a rubber spatula so you can scrape the sides of the bowl, pour the warm corn syrup all at once into your melted white chocolate, Stir quickly, using a folding motion, scrape the sides of the bowl. Your goal is to incorporate the corn syrup COMPLETELY into the white chocolate without it becoming too oily and separated. You will notice that as you stir, the chocolate will seize into a thick gooey mass and will clean the sides of the bowl. Look closely to make sure you don't have any streaks of unincorporated chocolate.....this unincorporated chocolate will become lumpy grains later, and you don't want that.
The mass will seem a little oily, that's OK. But the more you stir, the oilier it gets, and you don't want oil dripping off it either. It's a delicate balance.
Line a cookie sheet with at least 1 inch sides, or a rectangular pyrex dish with plastic wrap, so the wrap hangs over the sides. Pour your white chocolate mass into the dish or cookie sheet and press it down with a spatula to flatten it out all the way to the sides of the sheet or dish. Bring up the sides of the plastic wrap to completely cover your brick of modeling chocolate. Place the whole thing in the fridge for a couple hours.
After it's set, bring it out to come to room temp. When it's room temperature, break up the modeling chocolate in easy to handle pieces. The pieces will look very rough. Now you have to knead it smooth. Depending on the ambient temperature of the room and the strength in your hands, you may have to stick the pieces in the microwave to warm up for a few seconds so they are kneadable. Be careful not to overwarm the pieces, because the warmth of your hands will do the rest of that work for you. This is the moment of truth when you'll know how well you stirred it. If you have a lot of lumps and grains, then you know you didn't stir well enough, or perhaps burned the chocolate a little. Most of the time you can knead or roll them out, or if they're really big you can pick them out. But, if you did it right, this shouldn't be a problem. Once kneaded, the chocolate is ready for use. You can color it with any type of coloring....I prefer concentrated gels or powders. Liquid is not recommended, just because it makes the chocolate too slack without coloring it completely enough. However if you desire a light pastel, liquid is ok.
When working with modeling chocolate and especially when you are doing ribbons and such, I highly recommend using a manual pasta machine. The evenness and thinness of rolling is invaluable. At about 40 bucks a pop, it's a reasonable investment. I have one that I use JUST for modeling chocolate and nothing else.
When working with modeling chocolate, dust with cornstarch....not flour or powdered sugar. Always take care to brush off excess cornstarch with a soft brush when your pieces are done.
There are lots of places on the web that sell powdered color. You can google it, or go to Sugarcraft.com or Country Kitchens.