After spending a few days developing a website, I asked the client to test the new features. He sent me an email complaining that he could not make a new account with the current version of the website.

Client: The font is really bad. I can’t read it and I keep getting some errors during the sign up process.

Me: Where, exactly, is the website not readable? What’s the exact error?  

Client: At the bottom of the signup form, there is a text with a really bad font. I can’t read it and it’s asking me to retype it!

He was referring to the captcha system used to verify non-bots.