How to highlight the design and structure of wood

The patterns that we see on the wood are the result of the annual rings of the trunk being cut into different sections. The annual rings represent the mass of wood deposited annually by the tree. Between that deposited in the first period of the growing season (spring, early summer), called early wood and the second half (summer, early fall), late wood, there are differences in density, hardness, strength, color, number and arrangement of pores. The processing required to obtain the lumber or veneers causes these differences to produce patterns.

There are several ways to section the trunk to make lumber. Relative to the central axis, the wood can be cut perpendicular to the axis or along it. Cutting perpendicularly results in rounds in which the annual rings look like concentric circles. Cutting along the trunk can be done in three ways: parallel to the central axis (longitudinal cut), parallel to the radius of the circle represented by the trunk (radial or quarter cut) or tangential to the annual ring (tangential cut). The longitudinal and radial cuts produce parallel line drawings, while the tangential cut produces the wavy line drawing called a cathedral or flader. You can find information on the cutting methods to obtain veneers here.

In some species, there is no significant difference in color between latewood and earlywood, and the pores are small and inconspicuous. Cutting these species results in a uniform surface with a dull, unidentifiable pattern. There are, however, ways in which the pattern can be emphasized, starting from the difference in density and hardness.

Staining, the easiest way to highlight wood design.

Highlighting is possible due to the different density of the wood. The color will be absorbed differently in early wood than in late wood and so the pattern will be more visible. This is the case with lime or poplar which, uncolored, is very uniform. Staining, even with very light colors, will add to the aesthetics.

The method of application is also important. If the stain is applied with a cloth, sponge, roller or wiped off after spraying, the wood design will become more visible. Wiping will push the color into areas where the wood absorbs, but will remove it more quickly where absorption is slower. This will increase the difference in color between the two types of wood, highlighting the design.

Solutions based on colorants, not pigments, are best suited to achieve this effect. The latter are usually called evening baths. Pigments do not dissolve in water or organic solvents and are therefore not absorbed into the wood. They remain on the surface and cover differences, evening out the appearance of the wood. The colorants dissolve, the resulting solution is absorbed into the different wood and the design comes to life. The disadvantage is that it will also bring out the defects in the wood, so the wood must be very well prepared beforehand. Recommendations for stain-free staining here.

The range of coloring solutions is large and it is often difficult to identify the one that does not contain pigments. The most handy criterion is price. Pigments are generally more expensive, so solutions containing them will also be more expensive. You should also avoid baths with the word standardising.

Marking pores or patinating wood with a large difference in density will make the design more visible

There are also species with large pores in which, due to the uniform color, the pattern is not very evident. This is the case with ash, which is very similar to oak but lighter in color and more uniform. In this case, a very good solution is pore staining. They use special coloring baths or solutions, sometimes called skatesThe process is also known as patination. The principle of the method is that these solutions bath or be pushed into the pores (by wiping), making them more visible.

Skates can also be used on resinous wood, even if it has no pores. The large difference in density between latewood and earlywood will result in a reverse coloration after patina removal. Late wood, darker and much denser, will not be able to be colored, whereas early wood will be intensely colored, being more light. The result will be a more vivid, more visible, a  "negative" of the initial drawing.

Structuring the wood surface by sanding, brushing or sandblasting

It is the difference in hardness between the early and late wood that makes the design visible in this case, becoming three-dimensional (3D). With different abrasive sanding methods, the softer and more loose early wood will be easily removed, while the late wood will remain in relief due to its higher hardness. The method is commonly called structuring. The effect mimics the look of old, weathered wood, often found in old village fences. Softwoods are often subjected to structuring because they do not require much effort, but the method is also used on oak and other hardwoods.

Structuring can be made by sanding, brushing or sandblasting. When structuring by sanding, initially coarse sandpaper (60-80) is used to remove the wood, then finer sandpaper (120-180) is used to smooth the grain. Brushing is done with wire brushes, by hand or mechanical. When brushing by hand, it is recommended to use thicker bristles to avoid scratching the wood. For sandblast Special spray guns are used that spray sand or other abrasive materials onto the wood surface under pressure. The resulting surface is contoured and very smooth, with the fine sand best reproducing the natural structure caused by atmospheric dust.

Structuring is also used by artists. By sanding thin pieces of wood (veneer) they manage to completely remove the early wood, the resulting effect is transparent wood.

Burning dyeing

Burning, which is also the basis for a well-known method of protection from the elements, fungi and insects (Shou Sugi Ban), can highlight the wood's design. The method is based on the different burning resistance of the two types of wood. Early wood burns faster, while late wood is more resistant. Slight surface burning will emphasize the design of the wood, while the deepest, followed by brushing, will structure it. A special effect is achieved if the lightly brushed wood, without completely removing the blackened parts, is then stained in pastel colors.

I hope you find the above information useful. As always, additions are welcome. And if you have any clarifications or questions, leave them below, in the dedicated space. I'll be sure to reply.