Table 4. The penetration depth of wood surface after chemical treatment

Species	Conditions	Longitudinal direction (mm)	Tangential direction (mm)	Radial direction (mm)
L. kaempferi	P-4	2.3 (0.96)	1.3 (0.50)	1.8 (0.29)
	P-8	3.3 (0.96)	1.8 (0.50)	4.0 (0.41)
	1/2P-4	1.3 (0.50)	0.9 (0.25)	0.9 (0.25)
	1/2P-8	2.5 (0.58)	1.5 (0.41)	2.0 (0.41)
Q. mongolica	P-4	1.9 (0.63)	1.1 (0.25)	1.6 (0.48)
	P-8	3.0 (0.08)	2.4 (0.48)	3.0 (0.71)
	1/2P-4	0.9 (0.25)	0.5 (0.08)	1.0 (0.08)
	1/2P-8	1.0 (0.08)	1.1 (0.25)	1.6 (0.25)