These colour variations and markings occur because of natural causes, and are influenced by many factors including: oil types, minerals, water levels, available sunlight, temperature, and genetic composition. This variation in colour is what gives our products their unique character. To have complete uniformity would require only specific parts of the tree to be  used. This would result in a recovery rate of less than 30%. This means 70% of the timber would not be used - which is at odds with our sustainability ethos.