A new yarn-bombing campaign is set to spring up all over the country in a bid to highlight the importance of regular blood donation.
NHS Blood and Transplant (NHSBT) asked crafters to pick up their red yarn and create woolly red blood drops a few months ago, with 8,000 made and handed in as a result.
Now, these striking decorations are to be hung from trees in public places like town centres, shopping precincts and railway stations across England and North Wales alongside publicity material featuring the tagline 'blood does not grow on trees'.
It is hoped that young people in particular will see the yarn-bombing and take on board the message that a constant supply of blood is necessary to meet the demand, as the number of 17 to 24-year-olds giving blood has decreased dramatically in recent years.
Indeed, only 15 per cent of active donors are now in this age group - and just four per cent of Britain's total eligible population donate blood to begin with.
Rebecca Willis, 18, who writes a knitting blog and whose grandfather's life was saved by a blood transfusion, helped to launch the yarn-bombing campaign in her home town of Dartford.
She was one of the people who developed patterns for the blood droplets and she said it has been a humbling experience so far.
"It has been fascinating and truly touching how many people picked up their knitting needles and crochet hooks (sometimes for the first time!) in support of this campaign," the teenager added.
NHSBT collects 1.8 million units of blood each year, but hospitals in England and North Wales need around 7,000 units of blood every single day to treat their patients.
It is not the first time lately that knitting has been used to highlight a health-related issue. Earlier this month, we reported that Glasgow Caledonian University was asking craters to make woolly bacteria to be used as part of a drive to encourage children to wash their hands.