Air China 3,6,7,9,19,20,21,64,68,69,70

China

• paper 
• flat base
• tear off strip
• attached tab
• straight cut

6,70:

6:

• manufacturer in right gusset:

70:

• no manufacturer

3,7,9,19,20,21,64,68,69:

Variations :

7:                 tape on base

20,21,64:   smaller arrow

20:              other perforation

64,68:         TEAR OFF under Chinese letters

• Gap between red logo and Air China is different

          64:   6 mm

          68:  13 mm

69:               TEAR OFF different letters

9:

• pointy bottom
• manufacturer in left gusset: