Thankful for Friends, Food, Family and Yarn mug. back reads: But mostly YARN. At last a mug for someone who knits or crochets that speaks the truth...after all, you can't make a sweater using Grandma. The interior is soft grey. Created in my New Jersey studio from stoneware clay and kiln fired to over 1900 degrees. This mug measures 4 x 4 and holds 16 oz. All glazes are lead free and non toxic. This item may be placed in the dishwasher or microwave- made to be used and enjoyed.