Our prime grade flooring products have few, if any, knots and these will be of minimal size. There will also be a minimal amount of sapwood and filler, if any at all. The colour of the filler is intended to complement the natural structure of the wood, where features such as knots are in contrast to the surrounding timber, and it may vary from batch to batch. There will be a relatively small amount of colour variation in the timber itself, unless a reactive finish such as smoking or fuming has been used to accentuate the variation.