I just zip them and take a sharpie marker and number them in 1-2, 3-4, 5-6 etc. #1 on the top piece and #2 on the bottom piece, so on and so forth.That way I know what piece goes to what half of fillet. Along with a letter for the corresponding species, W for walleye, N for northern, P for perch..................... You know...........just in case.