240	MODERN PAPER-MAKING
way of increasing the drag upon it is to hang a felt cloth on it from above;
this acts as a brake and reduces its speed.
None of these methods of 'dragging' the dandy roll is to be recommended.
Both are inclined to cause 'pick-ups'. A far better way is to run a turn'or
two of tape round the ends of the roll. This will give a more regular distance,
and if the paper is of thin substance will take the driving of the roll off the
stuff a little and prevent *pick-ups'.