Thermal-dye-transfer labels, and pre-label media from which they are made, comprising an extruded pragmatic polymer film comprising a microvoided layer, a continuous phase of which comprises a polylactic-acid-based material wherein the microvoids are formed by employing relatively smaller size void initiators, including, for example, various inorganic particles such as titanium dioxide. A method of making sheets for such media is also disclosed involving an extrusion process. High-quality pressure-sensitive labels for application to packages are obtainable by the present invention.