# \hbox spread in plain TeX

I want to learn Plain TeX to understand the underlying mechanics of TeX and friends. I am trying to reproduce the spacing of this dedication from the Spanish music-theory treatise, El porque de la música, by Andrés Lorente (Alcalá, 1672).

Here is the best I can do so far:

Why does the \hbox spread \hsize command create an \hbox larger than the \hsize?

(Also, why is the spacing so uneven between lines?)

\hoffset=0.5in
\hsize=5.5in

\font\Huge=cmr10 at 48pt
\font\Large=cmr10 at 36pt
\font\large=cmr10 at 24pt
\font\big=cmr10 at 16pt
\font\mainfont=cmr10 at 12pt
\mainfont

\def\centertitleline #1 {\line{\hss #1\hss}\titlelineskip}
\def\titlelineskip {\par\vskip 1ex}

%****************************************

{\big
\centertitleline{bida sin mancha de Pecado Original, en el}
\centertitleline{Primer Instante de}
\centertitleline{su Ser.}
}

\bye

• The spacing is uneven as you have not increased \baselineskip so you are setting large text on a small baseline, so TeX can not achieve even spacing – David Carlisle Sep 18 '14 at 16:19
• Thanks. I will look into defining a font-size command that also changes the baselineskip. For this example, perhaps I also need looser inter-character spacing by changing glue settings. – musarithmia Sep 18 '14 at 16:44
• Or just use latex, where size changing commands are set up to change the baseline already:-) – David Carlisle Sep 18 '14 at 16:55

spread is that much extra width, you want to which specifies the final width

Here's some additional ideas for you for use with XeTeX:

\uselanguage{spanish}

\def\mainfont{EB Garamond}
\font\hugefn="\mainfont:letterspace=10" at 30bp
\font\largefn="\mainfont:letterspace=5" at 22bp
\font\bigfn="\mainfont:letterspace=5" at 14bp % NOTE: \big is already defined!
\font\mainfn="\mainfont:+hlig;+onum" at 12bp % historical ligatures, old style numbers
\mainfn

\def\gaps{\spaceskip=.3333em plus 1fil }

\hsize=19pc
\leftskip=0pt plus 1fil \rightskip=\leftskip \parfillskip=0pt \obeylines
\openup2\jot \line{\hugefn\gaps A MARIA SAN\rlap{-}}
\line{\largefn\gaps TISSIMA \raise.5ex\hbox{,} NVESTRA}
\line{\bigfn\gaps ABOGADA , Y SEÑORA , CONCE-}
\openup-1\jot bida ſin mancha de Pecado Original, en el
Primer Inſtante de
ſu Ser.
\bye


• This is great! I will study it! I also want to see if it works with fbb or Cardo fonts. – musarithmia Sep 19 '14 at 0:21
• How did you adjust the baselineskips? – musarithmia Sep 23 '14 at 14:05
• @Andrew: With the \openup, which \advances all of \lineskip, \baselineskip, and \lineskiplimit by the amount of its dimen argument. The amount \jot is defined by default to be 3pt. – morbusg Sep 23 '14 at 15:27