I was looking at switching from Crisco to high ratio shortening. I have a hard time smoothing cakes with regular icing, so I currently use a crusting buttercream that uses equal amounts of butter and Crisco, then I use the Viva method to smooth my cakes. Does anyone know if I can use the Viva method with high ratio shortening? If so, do I substitute the same amount of high ratio shortening for Crisco? Thanks for any advice you may be able to offer. :)

I'm nost sure Becky, but I can tell you that I used to only use a crusting buttercream and always seemed to struggle with smoothing.  I switched to IMBC and it is much easier to work with!  You should give it a try.

Yes, if your current crisco recipe is crusting and can be smoothed with Viva, then use the same amount of high ratio and smooth it the same way.