d ust , ▁and ▁a ▁synth etic ▁res in ▁or ▁other ▁suitable ▁b inder , ▁which ▁is ▁pressed ▁and ▁extr ud ed . ▁Ori ented ▁str and ▁board , ▁also ▁known ▁as ▁fla ke board , ▁wa fer board , ▁or ▁chip board , ▁is ▁similar ▁but ▁uses ▁mach ined ▁wood ▁fla kes ▁offering ▁more ▁strength . ▁Part icle ▁board ▁is ▁che aper , ▁dens er ▁and ▁more ▁uniform ▁than ▁conventional ▁wood ▁and ▁p lywood ▁and ▁is ▁subst it uted ▁for ▁them ▁when ▁cost ▁is ▁more ▁important ▁than ▁strength ▁and ▁appearance . ▁A ▁major ▁dis adv antage ▁of ▁particle board ▁is ▁that ▁it ▁is ▁very ▁pr one ▁to ▁expansion ▁and ▁dis color ation ▁due ▁to ▁mo ist ure , ▁particularly ▁when ▁it ▁is ▁not ▁covered ▁with ▁paint ▁or ▁another ▁se aler . ▁ ▁Ori ented ▁str and ▁board ▁Ori ented ▁str and ▁board ▁( O SB ) ▁is ▁a ▁wood ▁struct ural ▁panel ▁manufact ured ▁from ▁rect angular - sh aped ▁str ands ▁of ▁wood ▁that ▁are ▁orient ed ▁length wise ▁and ▁then ▁arranged ▁in ▁layers , ▁laid ▁up ▁into ▁m ats , ▁and ▁bond ed ▁together ▁with ▁mo ist ure - res istant , ▁heat - c ured ▁ad hes ives . ▁The ▁individual ▁layers ▁can ▁be ▁cross - orient ed ▁to ▁provide ▁strength ▁and ▁st iff ness ▁to ▁the ▁panel . ▁However , ▁most ▁O SB ▁pan els ▁are ▁delivered ▁with ▁more ▁strength ▁in ▁one ▁direction . ▁The ▁wood ▁str ands ▁in ▁the ▁out most ▁layer ▁on ▁each ▁side ▁of ▁the