Comprehensive Glossary of Printing Terms

■ Prepress

White space / Gap

Explanation (translated): Refers to the white color of printing paper. During the printing or plate-making process, when multiple colors are overlaid, misalignment of positions may result in white edges appearing between adjacent colors.

Explanation: Trapping, also known as filling white or expansion and contraction, is mainly used to compensate for the white gaps between two adjacent different colors caused by inaccurate printing overlay.

When people face printed materials, they always feel that dark colors are closer to the eye, while light colors are farther away. Therefore, when trapping is applied to the original manuscript, efforts are always made to prevent light colors under dark colors from showing through, while the dark colors on top remain unchanged, ensuring that the visual effect is not affected.

Explanation: These are terms related to the photographic plate-making process during the era of hanging nets. refers to “flashing,” a technique used to compensate for insufficient light sensitivity in dark areas of the original image by briefly exposing the plate to light or using a flash to increase the depth of the plate, thus softening the image. is translated as “reversing,” a method where text or lines are printed with negative patterns, revealing the white paper. This technique is typically used to create contrast by leaving certain areas uncolored.

Explanation: In certain cases where screen angles overlap, this pattern can be visually acceptable when fine screen lines are added. However, in other cases where screen angles overlap differently, it may conflict with other colors, resulting in very unattractive large-scale patterns. This phenomenon is called “printing moiré,” also known as “moire pattern” or “interference pattern.”

Sawtooth Pattern：

Explanation: The teeth of a dog are unevenly shaped. When the image resolution is insufficient and enlarged, the edges will appear jagged, resembling the shape of a sawtooth.

■ Printing

Ghosting

Explanation: People who frequently read newspapers often notice faint lines, one or several, lighter than the printed text and images, on large-format actual photos or decorative bars with screen patterns in the newspaper. This is known as “ghosting,” which refers to unclear origin printing patterns or shadows.

Perfecting Printing

Explanation: This refers to a printing method that saves printing plates. After one side of the paper is printed and dried, the paper is flipped horizontally and vertically, which is called bottom side perfecting. When the paper tail is used as the reference point and flipped, it is called tail perfecting. It is a process of printing the back side of the paper without changing the printing plate.

Ink flying

Explanation: When the printing press operates at high speed but the ink viscosity is not sufficient, centrifugal force causes ink splattering.

Proofing

Explanation: Printing a sample draft in advance using a proofing machine before formal printing.

■ Binding

Bleed

Explanation: Bleed in printing refers to extending the design beyond the product’s outer dimensions, adding some pattern extensions in the trimming position, specifically for use by various production processes within their process tolerance range to avoid white edges or cutting into content after trimming. The standard size for bleed is 3mm.

Recto

Explanation: The page where the first code of the book version is located is called the recto. The page where the second code is located is called the verso. Recto and verso are collectively referred to as one set, one sheet, or one frame.

Saddle Stitching

Explanation: Saddle stitching is a binding method where the book cover is matched with the book block to form one volume. It is then stapled along the fold using wire staples on a machine, followed by trimming the booklets.

Perfect Binding

Explanation: Perfect binding is a method of binding where the pre-assembled booklets are sequentially aligned and bound together by threading through the last fold and locking the booklets tightly.

Plugging Cloth

Plugging cloth, also known as headband cloth, plugging fabric, etc., is a type of processed fabric strip with thread ribs, used to paste on the upper and lower ends of the spine of a hardcover book block, that is, to plug the cloth at both ends of the spine.

Format

Explanation: Format refers to the size specification of the pages of a publication, that is, how many pages are cut from one sheet of paper. Common formats include 32mo (cut into 32 pages, commonly used for general books), 16mo (cut into 16 pages, commonly used for magazines), and 64mo (cut into 64 pages, commonly used for small to medium-sized dictionaries, comics).