Epson ColorWorks C3500 Technical Reference Guide - Page 206

Black mark length Continuous paper (Blackmark) Center of black marks Center of paper width Center of paper width Paper feeding direction Interval of black marks Perforation position 0.5 mm or more (When using fanfold paper) Black mark width Media type Media source Paper width Black mark width Black mark length Center of a black mark Gaps between black marks Paper thickness Paper core External diameter Winding direction Plain / Matte Roll paper 30 to 108 mm {1.18 to 4.25"} 13 mm {0.51"} or more 4 mm {0.16"} or more (with a width of at least 4 mm around) 8.5 mm  1 mm {0.33  0.039"} 8 to 1117.6 mm {0.32 to 44"} 0.084 to 0.124 mm {0.003 to 0.004"} External diameter: 44.1 mm {1.74"} or more Maximum 101.6 mm {4"} Printing face must be facing outside. Do not use the paper with a hole or cutout. Black mark receipt 206