... (pin knots allowed, <1mm), little sound knots, <5mm, mineral lines & sapwood, B GradeDead knots <5mm, sound knots<10mm, ... knots <10mm, sound knots<30mm, sapwood & mineral lines, much sapwood & unlimited mineral lines.D GradeAll defects allowed, some defects can ... be repaired by putty.we can offer paulownia , chinese fir, poplar, pine boards ...