This may be very late but someone later on may be browsing through and find this helpful so I will post... One trick that I have used in the past is to use two different maps as in M2 and M3 since the seams are different. If you are going to make an M3 texture start on a M2 template and just do the areas where seams are for M3 meet and then convert the map to M3. Once you open your new M3 map you will see some areas around the edges are now done and you can now proceed to filling in the interior (main) portions. It seems to work for me Japes