Luc(as) de Groot produced his first commercial variable font in 1992, before having the Internet or PDF files. This was an arrow font for a signage company in London. By moving the sliders for weight and angle, 18 different arrows could be fine-tuned so that they would be a match for any typeface.
He prepared two non-editable documents with embedded images, which are reproduced below. The first one explained how to install the font. The second file told designers how to use the font. The files – reproduced below – could be opened with SimpleText, the default text application on pre-OSX Macs (the successor of SimpleText, named TextEdit, can still open these documents, but refuses to display the embedded images).