Table 6 Colour change of the Holmen paper caused by the accelerated aging (±  SD)

Wallmaster

3.88 (± 0.14)

− 1.53 (± 0.08)

0.55(± 0.06)

4.21 (± 0.15)

2.69 (± 0.14)

Wishab

3.88 (± 0.20)

− 1.37 (± 0.21)

0.50 (± 0.06)

4.15 (0.24)

2.63 (± 0.21)

Groom/Stick

3.88 (0.15)

− 1.52 (± 0.13)

0.59 (± 0.07)

4.21 (± 0.15)

2.69 (± 0.15)

Faber Castell

3.81 (± 0.14)

− 1.49 (± 0.14)

0.57 (± 0.08)

4.14 (± 0.14)

2.65 (± 0.15)

Nitrogen jet

3.69 (± 0.19)

− 1.64 (± 0.22)

0.67 (± 0.07)

4.10 (± 0.15)

2.68 (± 0.17)

CO₂ snow jet

3.87 (± 0.15)

− 1.74 (± 0.16)

0.71 (± 0.09)

4.30 (± 0.13)

2.83 (± 0.15)

Reference

3.95 (± 0.10)

− 1.62 (± 0.11)

0.70 (± 0.08)

4.33 (± 0.12)

2.85 (± 0.13)