The concrete roman font designed by D. Knuth is a lovely one. I am looking for a way for it to be larger.
The current header I have is as follows
\documentclass[15pt]{article}
\usepackage[margin=1in]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{amsmath,amssymb,amsthm,mathtools}
\usepackage{thmtools, thm-restate}
\usepackage{changepage}
\usepackage[T1]{fontenc}
\usepackage{eulervm,eucal,eufrak}% the math fonts used in concrete mathematics
\usepackage{bbold}
\usepackage{concrete}% the concrete-roman, used in concrete mathematics
\usepackage{lipsum,hyperref,datetime2}
\usepackage[dvipsnames]{xcolor}
Attempts made
I have tried changing [15pt] in \documentclass[15pt] to [17pt] or [25pt]. It did not change any thing in the pdf file. I have also tried configuring with \usepackage[20pt]{concrete} and \usepackage[fontsize=20pt]{concrete} - also in vain.
Question
How to effectively change the font size for the document over all? I'm afraid I must figure a way to configure as well
\usepackage{eulervm,eucal,eufrak}.


articledoesn't have a 15pt option (unrelated to which fonts you use) you can use a class that does, eg extarticle or other classes with a larger size range eg memoir or koma or simply use\Largeafter begin {document}` – David Carlisle Jun 17 '21 at 23:3615ptto12pt(as15ptdoes not do anything so you are getting 10pt) – David Carlisle Jun 17 '21 at 23:49articleandextarticlework? – Student Jun 18 '21 at 00:07