How Many Fonts Do I Need Installed On My Computer

What is an optimum number of fonts to have on hand?

Can I just keep only the “Normal” fonts? An example I have 19 ANNUAL fonts; if I only keep the normal fonts it reduces the number to 5!

Perhaps I should delete all reasonably similar fonts.

My first computer only had 6 fonts in it! I get MakeUseOf each day. An answer there would be quite sufficient and may help others too.

By the way - I was born too late (1932) to get in on the computer age. I did all my calculations as an engineer with a slide rule!