Nicola Sturgeon has recommended that Scots wear cloth face coverings on public transport and in shops due to Covid-19.
Scotland's First Minister stressed the advice was precautionary and not mandatory and that she didn't recommend the use of masks for children under two.
At her daily briefing today, she said guidance has been published on the Scottish Government website.
In a government policy u-turn, she said science now shows there may be some benefit to wearing a face covering but should not be used as an alternative to other safety measure, such as hand washing and social distancing.
"What I don't want is people thinking they are invincible to the virus because they are wearing a face mask. You shouldn't think it gives you license to do the things the rules tell you you shouldn't be doing," she stressed.
"This guidance may well evolve and develop. We are not making it mandatory just now."
She said they could work well when people are in enclosed spaces with other people and situations where "it's not easy to keep the two metres distance."
The Scottish First Minister also announced an expansion of the testing regime for coronavirus.
Health boards will now test everyone aged 70 and over who is admitted to hospital for the disease, regardless of whether they have symptoms.
In addition to this, they will be tested every four days throughout their stay in hospital, she said.
"This will help us identify if the virus is being transmitted throughout a hospital," Nicola Sturgeon said.
