When referring to wood, the term “open grain” describes a piece of wood with large visible pores. The uniqueness of a piece of wood is determined by many factors, including color, hardness, and grain pattern. Grain patterns are formed by a tree’s growth patterns from season to season, and the way in which the wood was cut during milling. While the pattern can be controlled to some extent, the openness or closeness of a wood’s grain is determined by the species of tree it came from.

The size of a wood’s grain is comparable to the pores in skin, varying based on the tree’s properties and affecting the wood’s absorbency. Hickory and Oak are two types of wood that have open grain. While these woods may look similar visually, their grain size becomes most relevant when finishing a project made from them. Open grain woods have a tendency to absorb finishes unevenly, which can lead to disastrous results for a finely crafted project. To avoid blotchiness and uneven absorption, it is important to use a specific type of wood filler designed to allow for consistent and even absorption. These fillers are available in clear and tinted varieties, and should be used in accordance with the manufacturer’s instructions to achieve a smooth finish.