https://www.wilton.com/covering-cake-board-with-fondant/WLTECH-382.html
Covering Cake Board with Fondant
Give your cake a dramatic look by placing it on a base board covered with fondant. Cut cake boards 2 in. larger in diameter than your cake, unless otherwise directed, then roll out fondant about 1 in. larger than board size. Wrap board with foil.
Steps
Step 1 - Coat Board
Lightly coat board with piping gel to help the fondant stick to the foil.
Step 2 - Roll & Drape Fondant
Roll out fondant to desired size, 1/4 in. thick. Position over board using a rolling pin, draping fondant over edge.
Step 3 - Smooth Top & Sides
Trim excess fondant from edges under bottom of board. Smooth top and sides with Easy-Glide Smoother.
