In a $\rm \LaTeX$ guide found on the website of George Mason University, it’s said that Computer Modern fonts can look ugly.1 Like most Computer Modern users, I didn’t notice that until I wrote an article using $\rm \LaTeX$ last weekend.
If one thinks that downloading the Blue Sky fonts from the American
Mathematical Society is too troublesome, simply including the package
lmodern will do.
P.S. I have learnt an ImageMagick command from a Stack Overflow question to convert a PDF file to an image.4