Foreachcontainer,ensure90%twobigsidesclean,theotherbigsidehassoundknot(lessthan2cm)andwaterline,n
Eachboard,onebigsideensurenocrack,nowaterline,noknots,theothersideallowswaterlineand3cmsoundknot.
ABC grade mixed , one side edged and ending crack allowed( A grade 30%~35%、B grade 30%~35%, C gra