Order perturbations do not vary along chains. Order parameter of DPPC sn-1 carbons shown for same leaflet lipids (left) and opposite leaflet lipids (right) for bilayers containing DiI-C18:0 (A,B), DiI-C18:2 (C,D) and DiI-C12:0 (E,F). Shells n ≤ 3 are shown (gray dashed), with darker grays indicating increased shell number. Overall average sn-1 order of a pure DPPC bilayer (black solid) is shown for comparison. Error bars indicate the standard deviation.