there may be people reading this who are new to this case or who or not new to it but desire to learn more about these fibers , so here is a segment of an article by Pat Speer in regards the fiber evidence .
"Which brings us back to the 4-3-64 testimony of the FBI's fiber expert, Stombaugh...
He eventually discussed the fibers: “I tried to match these fibers with the fibers to the blanket, and found that they had not originated from the blanket, because the cotton fibers were of entirely different colors. So I happened to think of the shirt and I made a known sample of the shirt fibers…I removed fibers from the shirt to determine the composition of it and also the colors. I found that the shirt was composed of dark-blue, grayish black, and orangish-yellow cotton fibers, and that these were the same shades of fibers I had found on the butt of the gun… "
He then presented some photographs to prove his point: “Color photographs are very difficult to make microscopically because the color isn’t always identical to what you see in the microscope. So these colors are slightly off.” “These are the orangish fibers. The color is not exactly the same as what one would see under the microscope. However, you can see that the fibers on both sides, namely the fiber from the rifle, here…And the fibers from the shirt, which are on the left hand side of Exhibit 674, do match. The colors are the same and also, we find the same twist in the fiber.” He then moved on to the grayish-black fibers: “These are the gray-black cotton fibers and the color didn’t come out well on these in this instance because of time and color process limitations…The same would apply to Exhibit 675 as to 674, with the exception of the color. The color on these is much darker and we tried up to last night to duplicate the exact color and this is the best I could come up with under the time and color process limitations. It took us about four hours to make a photograph such as this.”
Well, this is a bit of a surprise. Stombaugh was unable to get his photographs to match and expected the commission to take his word for it that the fibers really did match, when seen under his super spiffy microscope. Of course, they did just that. Not surprisingly, a detailed report by Stombaugh, explaining how and why he came to his conclusions, when his photographs didn't even match, never surfaced. A defense attorney could get fat on this stuff.
Stombaugh then moved on to the dark blue cotton fibers: “the color match of the dark blue cotton fibers shows rather well in this photograph, Exhibit 676…" (When asked about a violet fiber in the picture) “I asked the photographer about this when he developed this and I said “Why did we get this; this is not in the slide at all,” and he said that is one of the orange fibers. They use different techniques in bringing out the blue and yellow-orange in a photomicrograph…this shade in the photograph is different from what that fiber actually is. It is in the development process. I am not too familiar with color photography. There is an art to it. However, I do know that there are times and technical limitations on the accuracy of color reproductions…I believe (I recovered) a total of six or seven fibers from the butt plate, and three of them are blue fibers and all matched…Two shades.”
When asked his conclusions, Stombaugh declared: “it was my opinion that these fibers could easily have come from the shirt…Mainly because the fibers or the shirt is composed of point one, cotton, and point two, three basic colors. I found all three colors on the gun. Now if the shirt had been composed of 10 or 15 different colors and types of fibers and I only had found 3 of them, then I would feel that I had not found enough, but I found fibers on the gun which I could match with the fibers composing the shirt, so I feel the fibers could easily have come from the shirt.”
Could Stombaugh really have stated that a rust brown shirt was made up entirely of dark blue, grayish-black, and orange-ish yellow fibers? I must admit I'm skeptical. Since when is there no brown in brown? His assurance that the fibers found on the rifle "could easily" have come from Oswald's shirt is also questionable, and notable for its lack of precision."
https://www.patspeer.com/chapter-4b-threads-of-evidence