OFFSET PRINTING DEFECT

1. Hickeys 墨屎 / 脏点: A hickey occurs when a piece of dust or random mote sticks to either the plate or blanket of the offset printing press or the printing medium, which causes an imperfection on the printed page 当灰尘、杂质或其他微小颗粒附着在胶印机的印版、橡皮布（Blanket）或承印材料上时，会造成印刷品表面出现不规则的脏点或缺陷。
2. Roller Mark 墨辊痕 / 辊痕: Roller Mark means the unwanted transfer of ink from equipment to a printed sheet. Can occur due to roller setting, pressure setting, blanket condition and subtrate. 指印刷设备上的墨辊在印刷过程中产生的不正常油墨转移，在印刷品表面形成痕迹。可能由**墨辊调整、压力设定、橡皮布状态及承印材料（Substrate）**等因素造成。
3. Pilling 掉毛 / 纸毛堆积: A printing problem characterized by the accumulation of paper fibers 一种印刷问题，主要表现为纸张纤维或纸毛在印版、橡皮布或印刷表面上不断积聚，从而影响印刷质量。
4. Paper Dust 纸粉 / 纸尘: Dusting is a defect that appears during offset printing, resulting from fine particles of paper being extracted by the blanket. Caused by the paper fiber condition and trimming process 胶印过程中，由于橡皮布将纸张表面的细小纸屑、纸粉或纤维带起并转移，从而形成的印刷缺陷。主要与纸张纤维状况及裁切工艺有关。
5. Ghosting Mark 鬼影 / 鬼影痕: Ghosting in sheet-fed offset printing refers to the phenomenon in which glossy darker areas are visible on the back of otherwise even-ly colored surfaces with high ink concentration. The image on the front side reappears in the ghosting area.  在单张纸胶印中，当印刷区域存在较高的油墨覆盖率时，纸张另一面可能出现与正面图像相对应的较暗或较亮的影像。这种由正面图像在背面隐约重现的现象称为 Ghosting（鬼影）。
6. Mottling 斑驳 / 墨色不均: Print mottle is usually the result of uneven ink lay or non-uniform ink absorption across the paper surface, especially visible in mid-tone imagery or areas of uniform color such as solids and continuous-tone screen builds. 通常由于油墨铺展不均匀，或纸张表面对油墨的吸收不一致所造成的印刷缺陷。特别容易出现在中间调图像、实地色块及连续调网点区域，表现为颜色深浅不均或表面呈现斑驳状。
7. Scumming 起脏 / 非图文区上墨: A generic term for the presence of ink on non-image areas of the printing plate, which can be caused by a variety of press conditions. The symptoms occur when ink randomly appears on non-image plate areas and scum cannot be washed off easily. 指印版的非图文区域出现不应有的油墨。通常与印刷机的运行条件有关。当非图文区域随机出现油墨，并且不容易通过正常润版或清洗去除时，即称为 Scumming（起脏）。
8. Set-Off 背印 / 沾脏: The reduction or discharge of a debt by setting against it a claim in favor of the debtor / ink transfer to other printed sheet (over density can cause this issue - ink transfer to other sheet @ not enough sprayed powder) 指印刷完成后，尚未完全干燥的油墨从一张印刷品的正面转移到另一张印刷品的背面，造成背面沾墨或污染。常见原因包括油墨量过高、油墨密度过高、喷粉不足或干燥不充分。