In 1942, the prior definitives were printed on watermarked blue bank-note paper.
The first stamps printed for German-occupied Guernsey are of the same basic deign as the first definitives printed for German-occupied Jersey.
Upon occupying Guernsey, the Germans began bisecting British 2 pence stamps for use on the island.
Shown below are the stamps of the GermanStamps.net Collection on the physical album pages.
German postage in Guernsey initially consisted of provisional bisects of British issues. In 1941, the Germans issued a standard definitive design which was used for the duration of the occupation.