Chemical cenzorship pics

09.03.1943 Letter from Fp.41000N : Kroat.Infanterie Ersatz-Regiment 369. Nachrichten kompanie , to Zagreb NDH .  Visible chemical censorship, blue line on the back of  cover . On the paper with text blue and pale white lines of chemicals are visible.

1944.(exact date unreadable) Cover of a letter sent from Krapina, NDH to Fp 56925E:  4.Kompanie,  IV.Ausbildungs-Bataillon ,  Kroatische Ausbildungs Brigade. Chemical censorship lines visible on the back of the cover.

06.09.1943 folded official German issued  letter-sheet ,sent from Fp.59875  Stab u. Einheit gemischte Ausbildungs-Abteilung, Kroatische Ausbildungs Brigade to Zagreb NDH.
On the front and back of  cover  are visible pale and blue line of  chemical censorship. When letter unfolds chemical censorship lines are even better visible on the both sides of paper.