I have a ratty but much loved ripple afghan that I made back in college (more than 40 years ago). When I told my granddaughter how old it was, she said she wanted one like it.
“What color would you like?” I asked.
“Pink!” she replied.
I found some variegated pink yarn, which makes it so much easier because there’s no switching of colors and less little tails that need weaving in. A pattern I bought off of Etsy was one of the easiest ripple afghans I’ve found.
After several months it was completed and I gave it to her today for her 8th birthday. I made sure to make it big enough so that she can use it into adulthood, and hopefully she will have it for the next 40 years!

