The results of an investigation of the incommensurate lattice distortions in lT2-TaS2 by real space transmission electron microscopy are reported. It is concluded that the presence of static periodic lattice distortions (PLDs) in thin films does not necessarily indicate that they are static in bulk material. It is shown that, although Moire fringes between misoriented regions of lattice often have the superficial appearance to be expected for PLDs, they can nevertheless be distinguished from them. The anomalous directions and spacings of PLDs in thin foil regions are interpreted in terms of the simultaneous presence of different basic PLD variants. The implications of this interpretation on the dangers of mapping flat regions of the Fermi surface from the observed PLD are discussed. © 1977, Taylor & Francis Group, LLC. All rights reserved.