Table 1. The formulation of the impregnating solution

No	Treatment
1	8% kak in pure water
2	10% kak in pure water (w/v)1)
3	8% kak in wood vinegar solution
4	10% kak in wood vinegar solution
5	8% kak in pure water plus 4% borax
6	10% kak in pure water plus 4% borax
7	8% kak in wood vinegar solution plus 4% borax
8	10% kak in wood vinegar solution plus 4% borax
9	No treatment (control)

w/v is the unit of weight per volume.