Their website states “The VIVA Holiday Art Studio Tour, always the first two weekends in December”. It appears they are accepting studio tours by appointment.
For over 25 years the artists on Vashon Island have opened their doors to the public for a visit in their art studios. What started as mostly ceramicists, the show has grown to include up to 100 Island artists including jewelry makers, textiles, glass blowers, photographers and painters. The tour spans two weekends twice each year in May and in December. Many artists demonstrate their craft and all are ready to explain their processes at locations ranging from artists’ studios to Vashon’s historic buildings. A number of fine shops and galleries also feature the work of Island artists and craftspeople. Local shops and various businesses around the Island will have maps of the various locations for you to pick up. More info: https://vashon-maury.com/vashon-island/art-studio-tour/ and http://vivartists.com/viva/