Hello ifotomagic,
Can you confirm which version of ArtRage for iOS you have?
If you have ‘ArtRage’ (the last version was 2.4.0) then 4096px will I think be the largest canvas you can make.
If you have ‘ArtRage Vitae Mobile Painting’ (current version 1.1.5) then you should be able to go to 6000px