▁interview ▁for ▁the ▁Smith son ian ▁Archives ▁of ▁American ▁Art ▁( SA AM ), ▁Glen ▁Mich a els ▁remembered ▁Al ps ▁as ▁" the ▁one ▁who ▁opened ▁my ▁eyes ▁to ▁Op ▁Art . ▁His ▁whole ▁design ▁concept ▁was ▁optical ▁ill usion , ▁taking ▁a ▁flat ▁surface ▁and ▁turning ▁it ▁into ▁a ▁sculpt ural ▁thing . ▁Exper iments ▁that ▁he ▁was ▁doing ▁that ▁were ▁so ▁fert ile ▁and ▁so ▁exc iting ▁I ’ ve ▁never ▁seen ▁anything ▁like ▁since ." ▁ ▁Development ▁of ▁the ▁col lag raph ▁ ▁Writ ers ▁on ▁the ▁subject ▁of ▁col lag raph y ▁are ▁careful ▁to ▁point ▁out ▁that ▁while ▁Glen ▁Al ps ▁developed ▁the ▁art form ▁and ▁co ined ▁the ▁term ▁" col lag raph " ▁to ▁describe ▁it , ▁he ▁did ▁not ▁" in vent " ▁col lag raph y . ▁Element ary ▁col lag raph ic ▁techniques ▁can ▁be ▁detected ▁in ▁prints ▁d ating ▁from ▁the ▁ 1 9 th ▁century , ▁and ▁the ▁development ▁in ▁the ▁early ▁ 2 0 th ▁century ▁of ▁coll age ▁as ▁an ▁art ▁form ▁led ▁to ▁the ▁idea ▁that ▁objects ▁( including ▁bits ▁of ▁paper , ▁fabric , ▁metal ▁and ▁sand ) ▁col lag ed ▁on ▁to ▁a ▁printing ▁plate ▁could ▁be ▁in ked ▁and ▁printed ▁for ▁text ural ▁effects . ▁Art ists ▁who ▁pred ated ▁Al ps ▁in ▁the ▁use ▁of ▁this ▁concept ▁include ▁the ▁Norwegian ▁R olf ▁N esch ▁and ▁the ▁Americans ▁Bor is ▁Mar go ▁( 1 9 0 2 – 1 9 9 5 ), ▁Ed