The correct answer to that question may surprise you!
It is “Your guess is as good as mine,” and there is a good reason for why it is so vague.
Being an extremely impatient person, I can totally relate to anyone who pesters their plasterer with this question. After all, you have saved up the money to get the job done, found the right plasterer (okay maybe it is a DIY job), bought all the right products and watched excitedly as coat after coat of plaster has painstakingly been applied to your old, crumbly wall. Of course, you want to get to the good bit – the painting.