Flat symbols to 3D print and glue onto the keys and knob caps. Each icon (a PNG or JPEG in voiceloop's icons folder: dark or opaque artwork) is scaled to fit size mm, square or round (knob caps are always round), and printed layers x layerHeight thick. The icon for one key or knob cap, by file name. Profiles exported from voiceloop 0.8.2 or later also carry icons that aren't built in, as base64 in the element's text, so the symbols work on another PC. Import saves them to the icons folder. Empty text means the icon is looked up by name.