▁aspect ▁ratio ▁of ▁the ▁finished ▁print . ▁ ▁Mag net ic ▁IX ▁was ▁used ▁in ▁the ▁more ▁expensive ▁cam eras ▁and ▁allowed ▁for ▁more ▁information ▁exchange . ▁Most ▁cam eras ▁with ▁magnetic ▁IX ▁automatically ▁recorded ▁the ▁expos ure ▁date ▁and ▁time ▁on ▁the ▁magnetic ▁layer , ▁with ▁more ▁advanced ▁models ▁allowing ▁the ▁user ▁to ▁specify ▁a ▁pred et erm ined ▁ca ption ▁to ▁be ▁printed ▁on ▁the ▁photo ▁or ▁record ▁the ▁expos ure ▁settings , ▁as ▁well ▁as ▁determine ▁print ▁aspect ▁ratio . ▁Mag net ic ▁IX ▁caused ▁some ▁problems ▁for ▁photo ▁process ors , ▁who ▁found ▁their ▁magnetic ▁reading ▁heads ▁had ▁to ▁be ▁clean ed ▁frequently , ▁or ▁that ▁their ▁equipment ' s ▁ability ▁to ▁print ▁this ▁information ▁was ▁limited . ▁ ▁Process ing ▁▁ ▁Un like ▁ 1 3 5 ▁film , ▁processed ▁( develop ed ) ▁A PS ▁film ▁is ▁stored ▁in ▁the ▁original ▁cart ridge . ▁For ▁identification , ▁every ▁roll ▁of ▁A PS ▁film ▁has ▁a ▁six - digit ▁ID ▁code ▁on ▁the ▁label , ▁which ▁is ▁also ▁stored ▁magnet ically ▁and ▁is ▁visible ▁on ▁either ▁end ▁of ▁the ▁processed ▁negative . ▁This ▁ID ▁is ▁usually ▁printed ▁on ▁the ▁back ▁of ▁every ▁individual ▁print . ▁This ▁ID ▁was ▁designed ▁to ▁be ▁an ▁additional ▁convenience ▁both ▁for ▁the ▁phot opro cess or ▁( who ▁can ▁easily ▁match ▁each ▁strip ▁of ▁processed ▁film ▁with ▁its ▁cart ridge , ▁and ▁each ▁cart ridge ▁to ▁a ▁particular ▁customer ' s ▁order ) ▁and ▁for ▁the ▁consumer , ▁who ▁can ▁easily ▁locate ▁the