For cakes that are stacked directly on top of each other, columns should be cut flush to the top of your cake.
Columns can be cut to longer lengths and allowed to extend above your icing to create air space between tiers when you prefer to add flowers or other decorative items between the tiers.
The columns were designed to sit within the column "guide" feet of the SPS (single plate system) Separator Plates. The SPS Separator Plate guide feet prevent the columns from moving or sliding, holding them securely in place.
Low cost enough to be disposable, but washable and reusable, if your cakes are always leveled to the same heights as the cut column pieces.