O - Mat is an interactive playing mattress for children. It consist of stuffed animal puzzle on the inner circle, and the background setting on the outer part. This play mat is an activity mattress that can be used as puzzle, as storytelling tools, and also to stimulate curiosity for children. Just grab the light pen and draw with lights, then find invisible images hidden under the leaf, rock, and even clouds! O - Mat is a collaboration work between Nesia Anindita and Pornpavee Ditcomeroeng for their first project at Child Culture Design Master program, Högskolan för design och konsthantverk, Göteborg Universitet.