Clip

A clip, comprising:

• an insertion piece to be inserted into a valley defined by forming a folded portion formed by folding a corner of a stack of a plurality of paper pieces;
• a front-side clamping piece to be brought into contact with a paper piece portion on a front side with respect to the valley;
• and
• a back-side clamping piece to be brought into contact with a paper piece portion on a back side with respect to the valley,
• wherein
• the insertion piece, the front-side clamping piece, and the back-side clamping piece are elastically and integrally formed so that the paper piece portion on the front side and the paper piece portion on the back side with respect to the valley are clamped between the front-side clamping piece and the insertion piece and between the insertion piece and the back-side clamping piece, respectively, and both of the paper piece portion on the front side and the paper piece portion on the back side with respect to the valley are clamped between the front-side clamping piece and the back-side clamping piece,
• the insertion piece, the front-side clamping piece, and the back-side clamping piece are elastically and integrally formed through formation in a spiral shape, and
• the clip further comprises at least any one of:
• a first crossing portion configured to allow paper pieces inserted between the back-side clamping piece and the insertion piece to be brought into contact with and pressurized between the back-side clamping piece and the insertion piece;
• or
• a second crossing portion configured to allow paper pieces inserted between the front-side clamping piece and the insertion piece to be brought into contact with and pressurized between the front-side clamping piece and the insertion piece.