PURPOSE: To make various kinds of data simply and accurately to prevent defects in patchworks by providing such a means as to make a cloth cutting-off data automatically based on a reference line data for patchworks which is memorized by one input.

CONSTITUTION: A board face of a digitizer 2 is affixed with, for example, a circular paper pattern 8, and points R1 through R3 that form the contour of the pattern are picked up by a pointing device 41 to input a reference line data D1 for the circular form, which is stored in RAM of a control unit. A display 4 displays a line that links the points R1 through R3. Further, a cutting- off data D2 of, for example, a circular form is formed automatically by offsetting a certain amount from the reference line data D1 into the inner side, which is stored in a floppy disk. Then, by inserting this floppy disk into a cutting machine and operating the cutting machine based on, for example, the cutting-off data D2, a circular cutting-off part is formed on a cloth set on the board.