The first version which I shall describe was shown me by my magic teacher 50 years ago and, to my knowledge, has never been written up in any magic books. The second version is one I developed and have used in many of my shows.
First version:
Magician borrows a gentleman's jacket which he hangs over the back of a folding chair. He then states he will show the audience his old "Knife Through the Coat Trick ". The magicians reaches to his table for a 12 inch butcher knife and a single half sheet of newspaper, which measures 11 by 14 inches. Holding the knife in the right hand and a half sheet of newspaper in the left, the magician takes a position next to the chair on which the coat hangs. He displays the knife in the right hand, bending his knees to get closer to the coat and strikes the back of the coat with the point of the knife, saying, "The knife will go right through here!" His left hand comes down with the newspaper in front of the coat momentarily and again the audience sees the magician strike the back of the coat with the knife. The next thing the audience sees is the knife blade penetrating the newspaper and being pulled through the coat with his right hand. The coat is returned to the spectator with no damage whatsoever.
I think one of the humorous spots of the trick is when the magician tells the spectator and audience what he intends to do.
Explanation: The chair (usually a metal folding type) with no back but a top back rest of approximately six inches at the very top. Another type is the folding (under taker-parlor wood type) with four or five wood slats in the back.
The half sheet of newspaper used should be folded down one-half inch at the top, which is the 11 inch end. This tells the magician that the point of the knife is in the fold without looking and that the knife is hidden behind the newspaper.
Working: The magician is holding the butcher knife in his right hand, the newspaper is in his left with a fold at the top. He stands beside the chair which faces the audience and actually strike the back of the coat with the point of the knife. For a brief moment he holds the paper just above the coat and transfers the knife from the right hand to the left behind the paper. He knows without looking that the point of the knife is at the top of the paper because the fold prevents it from going any higher. With the left hand holding the knife behind the paper and slightly to the left, the magician again strikes the coat, this time with his right index finger. The magician next places the paper with the knife behind it in front of the coat and the right hand makes contact with the handle through the cloth of the coat and is pushed through the paper. Some cloth of the coat comes through the hole in the paper as his right hand comes to the front and pulls the knife free for a spectacular finish.
Second version: Same type of chair, but newspaper in this effect is cut to a size seven inches by seven inches square, and the knife is a paring knife the measures approximately six and a half inches long. No fold is needed in the paper. Two knives are used. One is sharp and not prepared in any form. This knife is scotch-taped to the back of the chair in a position so that the handle will face the magician as he stands behind the chair. The second knife is on a pull which goes up the magician's right sleeve. The gimmicked knife has a hole drilled in the very top of the handle which has an elastic band running to a safety pin which is attached at the magician's right arm pit. Experimentation will determine the correct length of the elastic so that the knife can easily be obtained with the left hand and pulled down into view in the right. This knife should be dulled down so as it travels up the sleeve no harm will come to the magician or his clothes.
Working: Magician borrows a spectator's coat and hangs it over the back of the chair. He turns to his right, supposedly to pick up the knife and paper from his table. At this time he pulls the knife into his right hand; his left hand then picks up the paper. Of course, the audience should be made to believe he obtained the knife from his table. Because the elastic runs up the right sleeve, angles are almost foolproof when the knife is displayed. Magician takes his place beside the chair. (He is on the right of the chair as seen by the audience.) Showing the knife in his right hand he strikes the back of the coat several times, shows the knife again and lets it go up his sleeve while his right hand is behind the coat. He then, through the cloth of the coat, rolls the second knife down free of the scotch tape to a spot behind the paper and pushes it through. Knife can then be examined. The scotch tape remains on the back of the chair.
I believe one of the greatest advantages to the magician is the "pull" and its use should not be overlooked.
Many thanks to Joe "Ballard" Taylor for sharing this fine effect with us.