Avoiding confusion with shade guides

What seems logical to you when you write things down can often be taken in a totally different way by the person reading. We've all experienced that haven't we? You write an email/letter and get a response back that you weren't expecting, only to realise it was the way the email/letter was interpreted.

Here's an example with shades.

Answer this question... "If you saw a shade written down that said A4++, is that lighter or darker than A4?"

Most people would say that A4++ is darker.

What about this?

This shade came in to the lab today, so if A4++ is darker than A4, is A1++ lighter or darker than A1?

I know the dentist wants lighter... but surely lighter than A1 is 'A1--'?

So, be careful what you write on lab prescriptions and make sure it is not open to ambiguous interpretation... you may just get what you ask for!