Working mainly with mixed media, ink, acrylics, and collage, Tammik creates images that are playful, slightly abstract, humorous, and free-spirited. She has illustrated children’s books and regularly contributes to the magazines Täheke and Hea Laps. Her illustration work also extends to fashion exhibitions, festival posters, packaging, and wall graphics for the Children’s Hospital of Tartu University Hospital.

Her work has received several awards and recognitions, including the ADC Estonia Design Award, the Golden Egg Award, the Estonian Design Award, recognition in Estonian best-designed book competitions, inclusion in the White Ravens selection, and dPICTUS’s 100 Outstanding Picturebooks 2025. Books illustrated by Tammik have been translated and published internationally, including in Mexico, Spain, and South Korea.