This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Anyone having tried to typewrite on cards or heavy stock has doubtless experienced much trouble in getting the card to feed properly. If at all heavy, it will resist the curving so strongly that it will not be carried around the platen, and the edge of the card is very apt to catch on the pressure rolls and cause the platen to slip.
The remedy is very simple and consists in running a sheet of paper through ahead of the card until an edge of about 1/2 in. remains, then inserting the edge of the card inside of the projecting edge of the paper and turning the platen. The paper overlapping the card prevents the edge of the latter from catching on the pressure rolls and keeps it in close contact with the platen so that it will pass through without trouble. - Contributed by Thos. L. Parker, St. Paul, Minn.