Ancient painted wooden panels are an important part of our cultural heritage. Wood as a support has always been very popular and painted panels are currently present, in a large number, in many churches and museums. However, depending on conservation conditions, their shape may modify in time and if not properly controlled may lead to some sever damage to the artworks. The paper describes the results of a study on the measurement of paintings surface deformation carried out using two different commercial devices both making use of structured light. The main goal was to highlight and measure the reliability of the such 3D measuring techniques to evaluate deviations from planarity due to the curving and warping of the wood in order to document spatial deformation suffered by the painting and monitoring its conservation status.