Thin plywood as a material

Koskisen’s thin plywood is made from Finnish birch. We acquire the face veneers for our hardwood products (oak, cherry, teak, walnut) from our subcontractors. The veneers are made from certified wood raw materials. The birch veneers used in the production of Koskisen’s thin plywood are peeled from the most valuable, high-quality part of the special birch logs. Special birch log is the butt section of a mature birch, which has, for example, very few knots. After peeling, the veneers are graded. The best veneers are chosen for the face, and the rest of the yield is used in the sheet’s core structures.

Sustainable wood sourcing is of primary importance to Koskinen. Responsible wood sourcing that promotes the diversity and vitality of forest nature today enables forest renewal and ensures that there is enough wood as raw material for future generations as well.

Koskisen uses a chain of custody system in all procurement to ensure that wood material is sourced legally and ethically from reliable and identified sources. The origin of all raw materials is always checked so that the forests in protected areas are safeguarded and wood is not sourced from controversial sources.

Koskisen wood procurement

We primarily recommend reusing the material. Consider whether you could use the leftover material from a small piece of furniture for some other purpose. Plan how you can use the material in a way that minimises waste, and think about how you can utilise any leftover material, including sawdust. Small amounts of thin plywood waste can be burned as energy waste along with other combustible material in suitable facilities. Please consult your local waste management provider’s instructions.

The sheets must be stored horizontally in a well-ventilated space and protected from dirt and exposure to UV radiation. The storage conditions should correspond to the processing and use environment of the sheets due to humidity and temperature equalisation.  Variations in humidity and temperature can affect the performance of the panel made from natural birch material, including its flatness. Evenly distributed weight on top of the sheets helps the sheets to flatten out as straight as possible. Storing the sheets upright should be avoided. The sheets should be stored for a few days before working or machining to allow them to stabilise, for example, from variations in humidity during transport.

The grades of the face veneers of thin plywood sheets are AB/B. This means that the grade category of the sheet’s face is AB and its reverse side is B.

In the AB grade, the natural characteristics of wood are allowed, such as slight colour variation, veins and small splits and checks or overlaps. Grain deviations and 2–3 knots with a maximum diameter of approx. 5 mm per sheet are also allowed.

B is a face grade that features the natural characteristics of birch. A slight colour variation, small splits and checks or overlaps, veins, a slight flame-like pattern and a few knots or knot holes with a maximum diameter of approx. 7–8 mm per sheet are allowed across the entire surface.

Thin plywood is manufactured from peeled, unpatched Finnish birch, and the veneer is characterised by the wood’s natural variations. Grading is performed on full-sized sheet blanks (1,220 mm x 1,220 mm), which means that pieces that are cut to smaller sizes may occasionally have more of the characteristics of birch veneer than the grade specification allows.