esse ▁in ▁emb rac ing ▁un predict ability . ▁High ly ▁transl uc ent ▁and ▁pr one ▁to ▁acc idents , ▁water color ▁paint ▁will ▁blo om ▁in ▁un predict able ▁ways ▁that , ▁depending ▁on ▁the ▁artist ' s ▁frame ▁of ▁mind , ▁can ▁be ▁a ▁bo on ▁or ▁a ▁bur den . ▁ ▁History ▁W et - on - w et ▁painting ▁has ▁been ▁pract iced ▁alongside ▁other ▁techniques ▁since ▁the ▁in vention ▁of ▁oil ▁painting , ▁and ▁was ▁used ▁by ▁several ▁of ▁the ▁major ▁Early ▁Nether land ish ▁pain ters ▁in ▁parts ▁of ▁their ▁pictures , ▁such ▁as ▁Jan ▁van ▁E y ck ▁in ▁the ▁Arn olf ini ▁portrait , ▁and ▁Rog ier ▁van ▁der ▁W ey den . ▁Among ▁the ▁many ▁Bar o que ▁pain ters ▁who ▁fav ored ▁an ▁alla ▁prima ▁technique ▁were ▁Diego ▁Vel áz quez ▁and ▁Fr ans ▁H als . ▁In ▁the ▁Roc oco ▁era , ▁con no isse urs ▁appreciated ▁bold ▁alla ▁prima ▁painting , ▁as ▁exempl ified ▁in ▁the ▁works ▁of ▁artists ▁such ▁as ▁Jean - H on or é ▁F rag on ard , ▁Francesco ▁Guard i , ▁and ▁Thomas ▁G ains borough . ▁ ▁Since ▁the ▁mid - 1 9 th ▁century , ▁the ▁use ▁of ▁commer cially ▁produced ▁p ig ments ▁in ▁port able ▁tub es ▁has ▁facil itated ▁an ▁easily ▁accessible ▁variety ▁of ▁colors ▁to ▁be ▁used ▁for ▁rapid ▁and ▁on - the - spot ▁painting . ▁Im pression ists ▁such ▁as ▁Claude ▁Mon et , ▁post - Im