It's common to export graphics from Mathematica that are subsequently scaled to various sizes that cannot (at least not conveniently) be anticipated. This is problematic in cases where (as is common) fonts and line weights need to fixed (e.g. throughout a document or presentation, or simply to prevent a figure from looking ridiculous).
For example, if the default options for fonts and line weights are satisfactory, then
Plot[{Sin[x], Cos[5 x]}, {x, 0, 2 Pi}] will produce a figure with correct font sizes an line weights

and scaling this figure within Mathematica (e.g. by dragging the resize frame) will preserve these font sizes and line weights:

However, if I export the original graphic in a resizable format (i.e., choosing "Save Graphic As..." and specifying a PDF "Vector Representation", which, as far as I can tell, is the only form suitable for subsequent resizing), the fonts and line weights scale with the graphic

which is not the desired result.
Is there a way to generate and export graphics so that font sizes and line weights are preserved when the exported graphic is resized?

ImageSizeoption (e.g. forShow[]andImageResolutionfor export, though I only used the latter one forPNGimages, it might also work for the font size and line with inepsexports. $\endgroup$PDFexcept maybe using Javascript in Adobe Reader (which won't work in other readers). WithSVGit could also be done using Javascript if you plan to display the graphic in a browser (e.g., by catching theonresizeevent). Of course that goes into off-topic territory for this site. $\endgroup$