I'm about to make a batch of white chocolate buttercream icing and the recipe calls for 18 oz of white baking chocolate - to be coarsely chopped in a food processor.
I assume that I need the "bar" of chocolate (usually sold in 4 oz. bars) as opposed to a bag of white chocolate chips. Is there a difference? I noticed the bars are lot more expensive than the chips. Can I substitute the chips? Any suggestions would be appreciated...Thanks!! )

I would substitute the bar for the chips but chop them up with a knife. I found the chocolate would stick in a food processor.

I have been looking for a great white chocolate b/c also.I bought a block of white chocolate in bulk at the grocery store and had about the same result as I did with the white chocolate chips.
The bulk was still very pricey though.I didn't love the taste of the buttercream combo.I layered it with raspberry filling and it seemed to curdle.
I found the chips had the same result just not quite as tasty.
If you find a good recipe I would love to know.I need it for a wedding in May.

Thanks Krista and bigbie! You have been very helpful....I'm going to try it with the chips....keep your fingers crossed!

Krista- I'm using the White Chocolate Buttercream Icing recipe found on the Wilton website.....I'll let you know how it turns out.

Thanks again!