To achieve a good fold on the board, a proper crease must first be made. The board must not be scored (this will result in a partial cut on the paper’s surface), but must be pre-creased to form an indentation and bead which internally delaminates the board’s structure to allow it to fold along this bead. This requires the use of a creasing rule and channel.
Any conversion processes prior to creasing must not interfere with the folding characteristics of the board.
UV varnishing over the area to be creased can cause problems and should be avoided if possible. Over-printing the area to be folded, with a contrasting colour is not recommended. Once the crease has been properly made, the board should be folded so that the bead is inside the fold. Failure to crease properly may result in the board cracking along the fold.
If there are any doubts about the folding characteristics of a board, then a test fold should be done.