How To Identify Flexographic Printing?

Flexographic printing has unique printing characteristics and process characteristics. These features can be determined by looking at the appearance, touching, analyzing the printing process and comparing the results. The method is as follows:
Pay attention to fingerprints
Spot shape
Flexographic printing is using anilox rollers transfer ink. In the process of ink transfer process, it is easy to squeeze out the edges of the dots. Therefore, the dot is usually "concave" or "elliptical", offset dot and gravure printing point.
In highlights, flexographic dots appear "hollow," meaning there is not enough ink in the center of the polka dot, causing the area to become shallow.
Color Saturation
Flexographic printing uses transparent, low-pressure ink. Therefore, the color saturation of printed matter is relatively low, resulting in softer, more natural colors.
Flexo printing may produce slightly less color than offset printing, but this feature works better in package printing, where a softer color effect is desired. Solid Smoothness
The solid area of a flexo print may have a slight "ripple" or "orange peel" pattern, which is determined by the method in which the ink of the anilox roller is loaded and the elasticity of the printing plate. This is especially true when printing large solid plates.
This texture is typical of flexographic printing and can be observed with a magnifying glass or microscope.
Touch print quality
Plate Thickness
Flexographic printing plates thickness is generally between 1.7mm and 7mm, than offset plate (about 0.3mm thick) and gravure plates (thickness varies according to printing requirements, but generally relatively thin).
While it is not possible to determine plate thickness accurately by direct contact with the print, in some cases you can determine flexo printing indirectly by looking at the edges or back of the print and feeling the pressure of the plate on the paper or film.
Ink Drying Behavior
ink types commonly used in flexographic printing include hydro, UV inks and solvent inks. Hydrating ink and UV inks have unique drying behaviors, resulting in a unique feel. Hydrating ink creates a thin film printing press water on the surface of the printing press, making the surface feel smooth. UV ink after drying, the surface will form a hard film, giving a hard smooth clear feeling.
Characterization of Printing Process
Printing pressure
Flexographic printing uses light pressure to reduce the contact pressure between the printing plate and the substrate. This makes the edges of text and image softer, with no visible pressure marks.
Compared with gravure printing, flexographic printing produces less jagged or burred lines. Compared with offset printing, flexographic printing dot gain is lower, so that the depth of the image is clearer.
Registration Accuracy
a flexographic printing press registration accuracy is affected by a variety of factors, including plate cylinder manufacturing accuracy, printing cylinder installation accuracy, printing tension control. Generally speaking, the registration accuracy of modern flexographic printing presses is ±0.1mm.
When examining prints, you can determine if they are flexible by examining the alignment of multi-color overprinted patterns or text. If the overprint accuracy is high, the edge design is sharp, it may be flexible printing.
Comparison with other Printing Methods
Comparison with set-off
Offsctdrucked-in products are bright in color and rich in depth, with round polka dots and smooth, even surfaces. Flexographic printing, on the other hand, has a lower color saturation, jujube-shaped dots, and a slightly textured surface.
In addition, offset printing generally use PS version, PS version is thinner, the printing pressures requirements are higher; flexographic printing generally uses thicker PS plate, the printing pressures requirements are lower.
Comparison with Gravure Printing
Gravure printing can produce bright colors, thicker ink layer and a noticeable relief effect. Flexographic printing produces softer colors, thinner ink layer and smoother surfaces.
Gravure printing uses sharp square or diamond dots; flexographic printing uses jujube-shaped dots with softer edges.