The classification method of printed matter， and the papermaking method using printed matter

The purpose of the present invention is to provide a technique for easy and rapid sorting of printed matter suitable as a starting material for recycled paper. By illuminating the surface of printed mater with light and measuring the reflected light， printed matter that is difficult to recycle as waste paper can be identified. Specifically， by eliminating， from the waste paper starting material， printed matter that， when the printed matter surface is illuminated with light， exhibits an absorption band close to 1720 cm-1， close to 1260 cm-1， close to 1160 cm-1， or close to 700 cm-1， it is possible to efficiently make recycled paper of good quality from the printed matter. The purpose of the present invention is to provide a technique for easy and rapid sorting of printed matter suitable as a starting material for recycled paper. By illuminating the surface of printed mater with light and measuring the reflected light， printed matter that is difficult to recycle as waste paper can be identified. Specifically， by eliminating， from the waste paper starting material， printed matter that， when the printed matter surface is illuminated with light， exhibits an absorption band close to 1720 cm -1， close to 1260 cm-1， close to 1160 cm-1， or close to 700 cm-1， it is possible to efficiently make recycled paper of good quality from the printed matter.