PeachDrawing.Core
PeachDrawing.Core.Canvas
Canvas.InvisibleText Property
While true, text this graphics draws is laid out and embedded as usual but paints nothing (PDF text render mode 3), so it stays selectable and searchable over content drawn some other way - a bitmap of the same text, say. Backends with no notion of text extraction (a raster graphics) draw no text at all while it is set. Everything other than text is unaffected; callers set it around the text-only pass and clear it afterwards.
public bool InvisibleText { get; set; }