This is the README for the mweights package, version 2020-01-23. Many font families available for use with LaTeX have multiple weights, especially when originally aimed at use on the web. For example, Linux Libertine has both bold and semibold; Cabin, a sans-serif family, has four weights (regular, medium, semibold, bold); SourceCodePro, a monospaced family, has seven weights. Traditionally the type1-oriented support packages for such fonts re-define the standard \mddefault or \bfdefault macros. But this can create difficulties if the weight desired for one font family isn't available for another font family, or if it differs from the weight desired for another font family. For example, there is no medium weight font for Linux Libertine so that setting \mddefault to mb for use with Cabin will be problematic for Libertine. And \bfdefault cannot be both sb for use with Cabin and b for use with Libertine, or vice versa. This package provides a solution to these difficulties. The basic idea (due to Michael Sharpe) is that font packages should *not* re-define \mddefault or \bfdefault; instead they should define as many of the following macros as is appropriate: \mdseries@rm \mdseries@sf \mdseries@tt \bfseries@rm \bfseries@sf \bfseries@tt For example, \def\mdseries@sf{mb} \def\bfseries@sf{b} would be appropriate definitions for using a sans font such as Cabin with medium and bold, and \def\bfseries@rm{sb} would be appropriate for using a Roman font such as Libertine with semibold. These macros should always be fully expanded; if necessary, \edef should be used. The package re-defines standard selection commands for series (\mdseries and \bfseries) and family (\rmfamily, \sffamily, \ttfamily) to use the macros. It should be a RequiredPackage (for type1 font use only) in any such font package. This package need not be used with LaTeX releases after 2020-02-02 which will incorporate mweights functionality into the LaTeX kernel; the mweights package itself will actually not be loaded by the kernel. The package is licensed under the terms of the LaTeX Project Public License. The maintainer is Bob Tennent (rdt at cs.queensu.ca).