I am new to modeling chocolate, but need to make a chocolate lab (no pun inteneded) I thought I read somewhere that you aren't able to use chocolate chips, is that correct?

Thanks!

I took a class recently where the instructor melted 1/4 cup of karo syrup and a 12 oz bag of white chocolate chips. Worked like a charm.

I used a bag of chocolate chips and 1/3 cup karo. Works great. Got the recipe for it here on CC. I think the amount of Karo for white chocolate chips differs.

Interesting, I tried last night with a 12 oz bag of semi sweet cc and just over 1/2 cup of karo. I let it cool in the frig for several hours. Took it out and started working a small part of it and it ended up just being a chocolatey mess.

I make it quite often 12 oz. bag chocolate chips, 1/3 cup karo. PERFECT everytime

Yes the amout of karo is less, I believe, when using white chocolate.

How soon after you make it are you able to start working with it?

The directions I use is for the Modeling Chocolate recipe here on CC. After mixing in the Karo, I spread it out 1/2" think on a piece of wax paper and let it rest for 2 hours. I believe you can start using it then, but I have not needed it that quick. I then put it in a sealed plastic container. I does get a little hard as days pass and it sits in the container, but the warmth of the hands softens it up real quick. I roll it out and use it like fondant. The dark brown accents on my zebra purse in my gallery is all modeling chocolate. People like eating this for accents rather than fondant. I'm going to make a gavel out of it. I can't wait!

http://cakecentral.com/recipes/1608/chocolate-clay-modeling-chocolate

when making semi-sweet mc, i always just use nestle chips and it turns out wonderfully.
i would suggest melting in dlbe boiler instead of microwaving and i always age mine for 12-24 hours in the fridge (if i have the 24 hours, i use it).
then break off only what you need and let it come to room temp before kneading.
be sure to only knead to when chocolate starts looking glossy and then STOP (or you will get grainy soft chocolate).