Abstract: The present invention provides a dot film, a multi-layers optic sheet comprising the dot film, and a smart electric board having the multi-layers optic sheet attached thereto, the dot film comprising: a base layer made of a synthetic resin; a resin layer coated with a resin mixture on the rear surface of the base layer; and a dot layer on which fine dots are formed by printing such that a printing material permeates the resin layer, wherein the dot layer has a plurality of dots formed therewith which are spaced apart from each other at crossing points of virtual grid lines, and has location information encrypted therein so as to determine location information of an electronic pen when writing with the electronic pen.