This label is under Netherlands-Indie, just for comparison. Ref: AV 5
Günter Mair catalogue: NEI-A-1 (1930)
Identical to the above design but printed in lighter typefaces. This label
was used during the early years of the Netherlands-Indonesian Union,
under the title of the Republic of the United States of Indonesia
or "Republik Indonesia Serikat".
Günter Mair catalogue: IDO-A-1 (1949)
Printed in darker marine blue.
Günter Mair catalogue: IDO-A-4 (1975)
Similar to the above design but in sky blue.
This label already in used for 30 years until now.
Günter Mair catalogue: IDO-A-5a (1978)