To solve a problem of cut-off mark left by perforations on the four sides by cutting a sheet with the help of the perforations.

This sheet is constituted of at least a matrix and coating layers 21 and 22 joined together on the face 1a and the back 1b of the matrix 1 without interposing a tacky material. In addition, a slit groove 3 is provided which penetrates the coating layer 21 on the face, reaching a border 1b between the coating layer 22 on the back and the matrix 1 or near the border 1b. Thus the sheet can be cut along the slit groove 3.