How to define font size in plain TeX such that it works as font size defined in article?

Question

% gettingstarted.tex
\hoffset=-72.27pt
\voffset=-72.27pt
\hsize=72.27pt
\vsize=72.27pt
\special{papersize=\the\hsize,\the\vsize}

\parindent=0pt
\nopagenumbers

\input pstricks

\def\tiny{\fontsize{10pt}{12pt}\selectfont}

\pspicture(\hsize,\vsize)
\psframe(\hsize,\vsize)
\rput{45}(0.5\hsize,0.5\vsize){\bf\tiny xport}
\endpspicture

\bye

How to define font size in plain TeX such that it works as font size defined in article?

Answer 1

There's no font selection scheme in Plain TeX. There are some packages that provide an infrastructure:

• fontch
• plnfss
• ofs

If you need to match fonts used in LaTeX, use LaTeX.

One should also keep in mind that scaling the Computer Modern fonts is not a good practice.

Here are two samples; the first has "A test" printed with

• cmr10 scaled 250
• cmr10 scaled 500
• cmr5

The second sample is of "A test" printed with \tiny from LaTeX (class article at 10pt size):

It's clear that the third option in the first sample corresponds to \tiny.

Answer 2

The speed difference between doing this in plain TeX and LaTeX will not reasonably be measurable.

In any case, 10 on 12 pt is the default in plain TeX, so you don't need to change the font size.

Fonts are not commutative in plain TeX, so each one must be separately defined, eg \font\tiny=cmb10 at10pt -- that means you can get rid of the \bf as well.

Better, use LaTeX.