The grain boundary characteristics in the 1050, 5052, 5083, 6061 and 1420 LTSP Al alloys were examined using EBSD as a function of TMT and LTSP deformation true strain from 1.5-12.0. The grain boundary character was observed to evolve continuously during TMT and LTSP deformation. With increasing accumulated deformation strain, the bimodal grain boundary misorientation distribution gradually transformed into semi-random behavior. For different alloys under cold or warm working, the minimum working strain to achieve a semi-random grain boundary misorientation distribution favorable for GBS and LTSP varied accordingly. Only minor variation was observed for the CSL boundary fraction during TMT and LTSP deformation. Still over 80% of the MAB+HAB belonged to random higher angle boundaries that could proceed GBS. No apparent relationship was seen for the CSL population and LTSP performance.