This piece of fabric is from Fokker Dr. I 425/17, the Fokker Dr.I triplane which Manfred Von Richthofen crashed and died in on April 21st, 1918.  It is from the underside of one of the wings.  The fabric was initially covered in light-blue pigmented dope and then painted with a turquoise blue oil paint.  This oil paint was subsequently painted with vermilion red oil paint.  The light-blue pigmented dope is soluble in acetone whereas the turquoise blue and vermilion red oil paint are not.  The turquoise blue color you see are flakes of the vermilion red paint that have flipped over exposing the underlying coat.  Thread count is 54 threads per inch.  This piece measures 4-5/8 in. x 3-3/8 in. or 12 cm x 8.6 cm.  The last photo is a microscopic cross-section revealing the built-up layers.