, ▁such ▁as ▁interior ▁house ▁paint , ▁the ▁orange ▁pe el ▁texture ▁is ▁des irable . ▁ ▁In ▁this ▁case , ▁a ▁texture ▁paint ▁is ▁generally ▁applied ▁with ▁a ▁sp ray ▁gun . ▁ ▁The ▁texture ▁is ▁then ▁painted ▁over ▁with ▁the ▁appropriate ▁color . ▁ ▁When ▁painting ▁walls , ▁orange ▁pe el ▁can ▁also ▁develop ▁by ▁using ▁a ▁roll er ▁with ▁too ▁little ▁paint ▁or ▁too ▁thick ▁a ▁paint ▁and ▁the ▁surface ▁d ries ▁before ▁the ▁texture ▁can ▁level . ▁ ▁Me asure ment ▁ ▁The ▁instruments ▁used ▁to ▁measure ▁orange ▁pe el ▁simulate ▁visual ▁per ception . ▁Like ▁our ▁eyes , ▁the ▁instruments ▁opt ically ▁scan ▁the ▁w avy ▁light / dark ▁pattern . ▁Two ▁types ▁of ▁instruments ▁are ▁available ▁to ▁quant ify ▁the ▁texture ▁or ▁w av iness ▁of ▁a ▁surface : ▁ ▁Orange ▁pe el ▁meter ▁ ▁The ▁orange ▁pe el ▁meter ▁uses ▁a ▁las er ▁point ▁light ▁source ▁to ▁ill uminate ▁the ▁spec imen ▁at ▁a ▁ 6 0 ° ▁angle ▁and ▁uses ▁a ▁det ector ▁to ▁measure ▁the ▁reflected ▁light ▁intensity ▁at ▁the ▁equal ▁but ▁opposite ▁angle . ▁The ▁instrument ▁is ▁rolled ▁across ▁the ▁surface ▁and ▁measures ▁point ▁by ▁point ▁the ▁optical ▁profile ▁of ▁the ▁surface ▁across ▁a ▁defined ▁distance . ▁The ▁instruments ▁analy se ▁the ▁structures ▁according ▁to ▁their ▁size . ▁In ▁order ▁to ▁simulate ▁the ▁human ▁eye ' s ▁resolution ▁at ▁various ▁distances , ▁the ▁measurement ▁signal ▁is ▁divided ▁into ▁several ▁ranges ▁using ▁mathematical ▁filter ▁functions : ▁ ▁Wa ▁ 0 . 1 ▁.. ...