I have a 4 tier wedding cake to set up in the May weather. This is my 1st outside reception. Its all buttercream with black scroll work. Any tips or suggestions?? I started thinking.. oh my gosh.. the black will not run will it?? I am using black royal icing and piping it on the white buttercream.

I would use an all shortening recipe for your buttercream. I wouldn't trust real butter in that hot weather. As for the scrolls, I think royal icing is the only way to go on that. I think it would be fine, but you can always do a test on a cupcake a week before to see if it bleeds in the heat.

When my best friend got married it was the end of May and there was no trouble with it. We had an outdoor reception as well. It held up fine. Now that was before I started making cakes so not sure about if she used butter or shortening recipes for it but I personally like the 1/2 and 1/2 the best. I know I used Ednas buttercream last week and it was the BEST I have used and I don't think she would use anything that would melt on the customer, but you could PM her or email her and ask her.

Patticakesnc,
Would you please share Edna's BC recipe?
TIA!

I use a high ratio shortening recipe! No butter in mine just flavoring. I guess the royal icing will be fine on the buttercream. Experimenting to see if it runs is an excellent idea.

It will depend a lot on where you are & what the weather will be like that time of year.
I have used 1/2 butter, 1/2 shortening icing in July in central CA w/o problems. One in particular that I remember was set up outside w/NO trees or anything to block the sun
Royal should be fine on b'cream - no running. Make your black days in advance so it has time to develop. Fresh colored icing can run.

my icing doesn't melt, doesn't run, doens't bleed.
http://cakecentral.com/cake_recipe-6992-Indydebis-Crisco-Based-Buttercream-Icing.html

WOW! You convinced me Indydebi! Time to give it a try..