Chief amongst the reasons that someone decides to select wood veneer casework for their project’s interiors is the aesthetic beauty that it offers to the workplace environment. Whether a traditional species such as oak or maple are preferred; or if pursuit of an alternative such as birch, walnut, cherry or steamed beach is desired, a finished hardwood veneer can “dress up” the office, school or laboratory.
Today let’s consider what goes into selecting a quality veneer.
Traditionally veneer backs are graded in numbers 1-4 (with the lower the number the better the material). Faces are graded in letters (AA-A-B) with the double AA being the cleanest material. The Hardwood Plywood Veneer Association (HPVA) publishes two charts to render their gradings:
For Red and White Oak:
For Ash, Birch, Maple and Poplar:
The grading is tied to the natural characteristics to the types of wood and what nature delivers. Things like Pin Knots and Mineral Streaks are allowed a bit more in the heavy grain woods like oak, as the inclusion of these items are associated with the species. While you can see that color variation is more acceptable with the “clearer” grain species. The size of the components or flitches that make up a full 4’x 8’ sheet of veneer is the same for each grade and species.
Please note: The grading is done based on sheet size (4’ x 8’), not component size (i.e. individual door or drawer front). So, in each sheet of AA veneer for example, you will get components that will be A or B in nature.
VENEER SLICING METHODS
Veneer can be sliced in four primary fashions: Rotary, Plain Sliced or Plain Sawn, Quartered or Rift.
- Rotary: Broad sheets, wild patterns, the most inexpensive commercial grade approach. Rotary cut provides the largest yield and therefore is the most inexpensive slicing method to be used.
- Plain Sliced: A tighter cathedral pattern with the leaf width being determined by the log thickness. This slicing method is almost considered an “industry default” choice. It’s cathedral grain pattern delivers on the natural beauty of wood.
- Quarter Cut or Sliced: This narrow cut pattern tightens the grain, producing a pinstripe tightness and uniformity. As suggested by the name, the log is quartered into four equal sections and then sliced off to create the flitches. When this method is used with the oak species, medullary rays result; almost a “flaking” appearance often referred to as “figuring”.
- Rift Cut or Sliced: Similar method to Quarter Cut with the blade or knife turned to a 15 degree angle, eliminating the effect of medullary rays and therefore frequently used for cutting the oak species. The result is the same tight and uniform grain patterns.
The methods are listed above in ascending order of cost. The greatest yield achieved with Rotary, followed by Plain Slice, much lower yield and much higher cost with Quarter and Rift cut.
Once the species, grade and slicing method have been chosen, the final step is deciding on the appropriate method of matching your veneer components. There are two methods commonly referred to as Book matched and Slip matched.
- Book Matched: The individual components or flitches are stacked together and placed side by side in a manner like opening a book. The top component is turned over and butted to the component directly below. In this way, the grain patterns are lined up by using the back of one component and the face of the other. This is an excellent choice for plain sliced red or white oak and maple, where symmetrical grain alignment is of the utmost importance to appearance.
- Slip Matched: The individual components or flitches are stacked together and placed side by side by sliding the top component off and laying it beside the component directly under it. As the name suggests, by sliding or slipping the components together, the faces are used for both flitches, allowing for the most consistent approach to veneer color. This method is the preferred approach for all species that are Quarter or Rift cut.
In addition to these considerations there are also a couple of other matching techniques as it relates to wood veneer leaves within a panel face.
Balanced match: Each panel face is assembled from veneer leaves of uniform width. Panels may contain an even or an odd number of leaves, and distribution might change from panel to panel within a sequenced set…either in Book or Slip match.
Center Balance match: Each panel face is assembled from an even number of veneer leaves of uniform width, with a veneer joint in the center of the panel, producing horizontal symmetry. A small amount of figure is lost in this process.
Running match: Each panel face is assembled from as many veneer leaves as necessary. This often results in an asymmetrical appearance, with some veneer leaves of unequal width. Often the most economical method a the expense of aesthetics, it is the standard for AWI Custom Grade and must be specified for other grades.
See the rest of the specifying quality wood casework options blog series posts as they become available: