Here's how I setup and do mine, which will need adapting to a multi-label-width page, since mine are Avery 4013, "3.5" x 15/16" One Across". It is basically a strip of 12 labels on a single column. My \setlabel tunes the vertical extent of the content to fit the label space. If you think it is too big, add a blank line. In the preamble, I highlight some of the parameters that can be tweaked if I change label format.
Format can be adjusted to multi-label-width format by specifying a wider paper, removing blank lines between \setlabel entries on the same row, and by removing the \par from the definition of \setlabel. SEE BELOW 1ST SOLUTION.
\documentclass[12pt]{article}
\usepackage[paperwidth=4.3275in,paperheight=12in,left=0.4in,right=0.4in,
top=.63in,bottom=.12in]{geometry}% top= tuned to your printer
\usepackage{scalerel}
\usepackage[usestackEOL]{stackengine}
\parindent 0in
\parskip .24in% Related to label width
\usepackage{Palatino}% Pick a font with good stroke width
\newlength\htone
\newlength\httwo
\htone=.73in% related to label height
\httwo=.73in% related to label height
\renewcommand\stackalignment{l}
\strutlongstacks{T}
\def\setlabel#1{\hfil%
\rule[-\dp\strutbox]{0in}{\htone}\scaleto{\Longstack{#1}}{\httwo}%
\par%
}
\frenchspacing
\begin{document}
\setlabel{
Pastor Theophilus Jones\
St. Luke Lutheran Church}% Wife Betsy
\setlabel{
Dr. & Mrs. Greg Lastname & Family\
908 Streetname Dr.\
Lancaster, PA 17601}% Liz + Kenny and Susie
\setlabel{
Herr Doktor Johann Schmidt\
Birkenstrasse 27\
86240 Biburg\
GERMANY}% Mom's Uncle
\end{document}

MULTI-WIDTH
\documentclass[12pt]{article}
\usepackage[paperwidth=10in,paperheight=12in,left=0.4in,right=0.4in,
top=.63in,bottom=.12in]{geometry}% top= tuned to your printer
\usepackage{scalerel}
\usepackage[usestackEOL]{stackengine}
\parindent 0in
\parskip .24in% Related to label width
\usepackage{Palatino}% Pick a font with good stroke width
\newlength\htone
\newlength\httwo
\htone=.73in% related to label height
\httwo=.73in% related to label height
\renewcommand\stackalignment{l}
\strutlongstacks{T}
\def\setlabel#1{\hfil%
\rule[-\dp\strutbox]{0in}{\htone}\scaleto{\Longstack{#1}}{\httwo}%
% \par%
}
\frenchspacing
\begin{document}
\setlabel{
Pastor Theophilus Jones\
St. Luke Lutheran Church}% Wife Betsy
\setlabel{
Dr. & Mrs. Greg Lastname & Family\
908 Streetname Dr.\
Lancaster, PA 17601}% Liz + Kenny and Susie
\setlabel{
Herr Doktor Johann Schmidt\
Birkenstrasse 27\
86240 Biburg\
GERMANY}% Mom's Uncle
\setlabel{
Frau Doktor Johanna Schmidt\
Birkenstrasse 27\
86240 Biburg\
GERMANY}% Mom's Uncle
\end{document}

texdoc elguideis the manual forenvlab– egreg Dec 18 '20 at 22:15