I have an image which is a technical drawing. The original image has a white background (which I need to keep) and multiple colored lines, which must be all converted to black (think of it as the technical drawing of a machine). I can't find how to do it in Paint.NET 4.0.6. Using Adjustments\Black & White gives me back grayscale, which doesn't cut it: I need all lines to be the same (black), not some lines to be darker, and some others to be lighter (a few are so light, I can barely see them). I also tried playing with brightness & contrast, but I end up messing the background, which is white originally, and must stay so. Any suggestions?