The ECO wick is a flat, coreless, cotton wick with thin paper filaments interwoven for burn stability. The specially treated paper threads provide a controlled curling of the wick, making the ECO series self-trimming, which results in minimized mushrooming, soot and smoke. ECO wick is particularly successful in lower melt-point vegetable and paraffin waxes. Here is a link to a video that explains how to select the size wick you need. https://youtu.be/vYKiF54W0wY