I’ve done a few striped cakes and still can’t work out if it’s necessary to cover the cake entirely in fondant and then add stripes or just to stick the stripes to the buttercream.

I’m doing a vertical stripes cake this week and would rather not cover in fondant first. Will it work just as well with smooth buttercream?

I don’t see why not   

Should work just fine.  I would say it is only necessary to cover the entire cake with fondant first if that is the look your client wants.  If they only want the stripes as accent pieces then putting them on a buttercream coated cake would be perfectly okay.

you could also stripe it with buttercream if that works -- like a basketweave tip -- the smooth side

Thanks everyone. The cake is to be completely covered in alternating colored vertical stripes. I’ll try without the layer underneath. 

If it is to be completely covered with stripes anyway, there is absolutely no reason to cover it with a solid piece of fondant first.

What Sandra said.  Covering it in a layer of fondant only to cover that completely with vertical stripes of fondant is, in my opinion, a waste of fondant (aka money).

In my case, adding a whole piece of fondant, then covering completely with fondant stripes just means that I have to peel off two layers of fondant instead of one.  I hate it.