When printing picture books, the selection of glazing machine is coater. Different coating methods have different requirements for coating materials, mainly viscosity requirements. General high speed, low viscosity, such as high-speed picture printing gravure, Flexo machine glazing, printing speed is about 60-200m / min. If the viscosity is high, varnish transferred to the substrate less, and not easy to level, so the viscosity is less than 28s (coated four cups). When the machine speed is 20-50m / min, the viscosity of varnish can not be lower than 35S, generally 35-80s. The viscosity of UV oil is better than 100-200s when using offset printing press and relief machine.

一般印刷画册的时候先烫金后上光效果好，因为金膜层背面有粘性与印刷的纸张附着牢固，正面性好与Uv光膜附着牢。如果画册印刷的工艺只能先上光后烫金，如柔版画册印刷机、不干胶机，应该上uv油后经电晕处理再烫金才行，否则易出现金膜脱落现象。

Generally, when printing picture books, the effect is good after gilding, because the back of the gold film is sticky and firmly adheres to the printed paper, the front is good and firmly adheres to the UV light film. If the album printing process can only be polished and then gilded, such as flexographic album printing machine, self-adhesive machine, should be on the UV oil after corona treatment and then gilded, otherwise easy to appear gold film off phenomenon.

若此现象不严重，一般无重力摩擦是不会脱落的。像说明书，叠放时上下页摩擦力不大就没问题。而书就不行，因为包装叠放、运输时，上下书相互摩擦会将金膜磨掉。另外包装盒也不行，因为包装盒码放时，盒挨着盒相互摩擦。

If this phenomenon is not serious, it will not fall off without gravity friction. Like the manual, the friction between the upper and lower pages is not big, so it's OK. But books can't, because when packing is stacked and transported, the gold film will be worn off by the friction between the upper and lower books. In addition, the packing boxes are not good, because when the packing boxes are stacked, the boxes rub against each other.