The wooden Straja Church represents an interesting historical monument from Transylvania that still retains the original popular religious paintings with various degrees of degradation. This paper aims to present the scientific investigation results about the materials and methods used by the painter and his son for both restoration and conservation purposes, and also to enrich the knowledge regarding the work of this author in particular and Transylvanian historical religious art in general. The investigations were performed by means of X-ray fluorescence (XRF) spectroscopy, destructive and nondestructive Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC).