lywood , ▁U ps om ▁board ▁and ▁Mason ite . ▁The ▁coll age ▁materials ▁were ▁like wise ▁cheap ▁and ▁easy ▁to ▁find , ▁and ▁included ▁( but ▁were ▁not ▁limited ▁to ) ▁polym er ▁gl ue , ▁model ing ▁paste , ▁auto ▁put ty , ▁pl astic ▁wood , ▁ground ▁wal nut ▁shell s , ▁wood ▁sh av ings , ▁br ush ▁br ist les , ▁string ▁and ▁ass ort ments ▁of ▁paper , ▁card board ▁and ▁cloth . ▁These ▁were ▁" the ▁ess entials ▁of ▁image - making " ▁through ▁the ▁coll age ▁technique . ▁By ▁disp ens ing ▁with ▁the ▁metal ▁pl ates ▁and ▁special ized ▁plate - working ▁tools ▁of ▁traditional ▁int ag lio ▁print making , ▁col lag raph y ▁allowed ▁the ▁artist ▁" to ▁approach ▁the ▁plate ▁very ▁sp ont ane ously ▁and ▁directly ▁or ▁quite ▁deliber ately ," ▁as ▁the ▁artist ' s ▁idea ▁and ▁working ▁style ▁dict ated . ▁For ▁Al ps , ▁an ▁artist ' s ▁freedom ▁dep ended ▁on ▁the ▁ability ▁to ▁acknow ledge ▁" the ▁potential ▁of ▁the ▁moment " ▁in ▁express ing ▁one ' s ▁inner ▁vision . ▁The ▁artist ▁must ▁be ▁pre occup ied ▁not ▁with ▁the ▁means ▁of ▁creation , ▁but ▁with ▁ideas . ▁Therefore , ▁Al ps ▁said , ▁col lag raph y ▁was ▁the ▁ideal ▁technique ▁for ▁contemporary ▁graphics ▁because ▁it ▁allowed ▁the ▁artist ▁to ▁work ▁sp ont ane ously ▁and ▁to ▁fully ▁realize ▁visual ▁ideas ▁in ▁a ▁relatively ▁short ▁time . ▁ ▁S cul pt ure ▁