This is a piece of 5 color undersurface day fabric measuring 10 inches by 7 inches.  A rib tape running diagonally has been removed leaving a small coloration suggesting a pink or mauve rib tape, possibly indicating Albatros manufacture, possibly an Albatros D.V or, for example, an Albatros-made Fokker D.VII. This would have been on the underside of one of the wings. Handwriting on back reads "Souvenir du 9 Mai 1918 Regions de Montdidier Avions Allemand.  Abattu.  14 Sec. 19 toile de fuslage S. Lucien."  René Paul Fonck claimed 6 German aircraft on 9 Mai 1918 when he flew with Spa 103 including a 2-seater over Montdidierat at 1820, his 40th victory (page 219, French Air Service War Chronology); victories near Montdidier were also claimed by Capt. Henri-Joseph Hay De Slade. The drawing is from Holger Steinle's book, Halberstadt C.IV. The last image measures the number of threads per inch as 56.