A co-winding type thermal transfer sheet is constituted by forming on one surface side of a substrate film a heat-fusible ink layer comprising a pigment and a particulate binder, and causing a tracing paper to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer. The thus constituted co-winding type thermal transfer sheet is capable of providing an original image which can be reproduced by use of a blueprint process so as to provide blueprint images having a high precision and a high contrast. In addition, a co-winding type thermal transfer sheet may also be constituted by forming a heat-fusible ink layer on one surface side of a substrate film and causing a transparent resin sheet to be peelably bonded onto the heat-fusible ink layer by the medium of an adhesive layer containing a cross-linking agent. The thus constituted co-winding type thermal transfer sheet is capable of providing an image excellent in wear resistance on the transparent resin sheet. The transparent resin sheet after the image formation may be used as an OHP (overhead projector) sheet without contaminating the sheet having no liquid absorbing property.