[Tex/LaTex] Slant character manually in TeX coding

Question

How to slant some character in the text of roman font (I don't want to use italics coding)?

Answer 1

Slant font of plain TeX

The plain TeX format defines \tensl to hold the slanted (not italics) variant of the default CM roman font, from plain.tex:

\font\tensl=cmsl10 % slanted roman

It can be used via \tensl or the higher level command \sl:

Default font vs.~{\sl slanted font.}
\bye

For more details, see the answer of egreg.

Slanting with TikZ

TikZ can be used with plain TeX, it allows arbitrary slant angles:

\input tikz

\def\slant#1#2{%
  \tikz[baseline=(X.base), xslant=tan(#1)]
    \node[inner sep=0pt, xslant=tan(#1)](X){#2};%
}

Normal, \slant{9.46}{slanted,} \slant{45}{larger slanting,}
\slant{-15}{slanted to the left.}

\bye