▁in ▁D . C . ▁at ▁the ▁Jefferson ▁Place ▁Gallery ▁in ▁ 1 9 6 4 ▁and ▁Py ram id ▁Gallery ▁in ▁ 1 9 7 1 ▁and ▁ 1 9 7 3 . ▁ ▁Re ed ▁was ▁method ical ▁in ▁his ▁painting , ▁his ▁works ▁fall ▁into ▁considered ▁series ; ▁as ▁he ▁developed ▁and ▁ref ined ▁an ▁idea . ▁The ▁last ▁work ▁of ▁a ▁series ▁is ▁usually ▁the ▁largest , ▁most ▁complex , ▁or ▁has ▁the ▁greatest ▁clar ity . ▁In ▁ 1 9 6 5 ▁Re ed ▁created ▁his ▁well - known ▁series — the ▁Disk ▁paint ings — where ▁two ▁corners ▁of ▁different ▁color ▁are ▁set ▁off ▁by ▁a ▁diagonal ▁band ▁with ▁a ▁large ▁circle ▁at ▁its ▁center . ▁With ▁these ▁works ▁Re ed ▁bl ended ▁colors ▁by ▁over la pping ▁layers ▁of ▁separate ▁colors , ▁something ▁that ▁was ▁distinct ▁to ▁the ▁new ▁water - based ▁ac ry lic ▁pain ts ▁then ▁available . ▁Next ▁Re ed ▁created ▁compos itions ▁of ▁z ig z ag ging ▁stri pes ▁where ▁each ▁line ▁kept ▁its ▁pure ▁color ▁yet ▁created ▁secondary ▁colors ▁at ▁each ▁b end ▁in ▁the ▁Up start ▁series ▁of ▁ 1 9 6 5 . ▁Further ▁color ▁over la pping ▁was ▁expl ored ▁with ▁the ▁“ pla id ” ▁effect ▁of ▁gr ids ▁in ▁the ▁series ▁Inter change , ▁Inside ▁Out , ▁and ▁C oh er ence ▁of ▁ 1 9 6 6 . ▁One ▁of ▁Re ed ' s ▁C oh er ence ▁paint ings ▁belonging ▁to ▁the ▁permanent