I am having a heck of a time with my fondant! It looks perfect at first but later that day i see lines in the final finish. I am attaching pics so you can see!
What can I do to prevent this?
That is the dreaded cake bulge. Try using a really stiff buttercream dam a half inch around the filling. Let it settle after filling for about 3 hours with a tile or book on top of the cake to push the air out. I also let it settle more after crumb coat and icing before I put fondant on the cake. Hope this will help.