If your drawings printed by your local print shop are coming out too light, it is likely that they are converting your JPEG image files to a PDF format for printing. In doing so, quality is lost. If this is the case, save the drawing as a PDF file and have them print the PDF instead. The results will be much better.
Saving a drawing as a JPEG or PDF using Maximum quality may result in the line weights becoming extremely fine, especially the ‘0’ line weights. Use Medium quality for the best results.