GoKawiilDeveloper documents technique for variable-width Bézier curves in 2D graphics APIs
Luther Tychonievich, who built eight custom board-work applications for teaching since 2014, has published a technical post explaining how to draw variable-width Bézier curves using existing 2D graphics APIs. He notes these applications were created because he found no suitable commercial tablet tools for live classroom drawing, and built versions in both JavaScript and D using various rendering backends including SVG, Canvas, Cairo and GSK.