This invention relates to an in-mold label comprising a core layer with a first and second surface and a heat seal layer on the first surface of the core layer, wherein the heat seal layer comprises a polyolefin, having a peak melt temperature of less than about 110° C. and where less than about 25% of the polyolefin melts at a temperature of less than 50° C. as measured by differential scanning calorimetry. The label may also contain a skin layer on the second surface of the core layer. The invention also relates to plastic substrates bonded to the label. In another aspect, the present invention also relates to a process for in-mold labeling and a process for preparing an in-mold label.