Printing Industrial Knowledge
Aqueous Coating
A clear usually gloss coating that is in a water base and applied like ink by an offset printing press to protect and enhance the printing underneath. Water-based coatings are mainly applied using coating units, though sometimes they are also applied using a press inking unit. The layer thickness of the aqueous coating can reach 3 µm. Water-based coatings are not as glossy as UV coatings.
Aqueous Coating is usually the least expensive gloss coating option.
They are often promoted as more environmentally friendly than UV coatings.
Blue-Line Proof
A photographic proof for checking layout and imposition accuracy before plates are made. Blue-line proofs give a 100% accurate idea of placement, but are not very useful for assessing tone or contrast. Blue-Lines are pretty much obsolete now.
Bond Paper
Bond Paper traditionally was a lighter weight paper, but currently can describe a variety of weights. Bond weight is determined by weighing 500 17”x22” sheets of bond grade paper.
Put another way, the "basis size" of bond paper is 17" x 22".
Common copy paper is usually referred to in bond weight - the most common paper is 20# bond (normal copy paper) followed by 24# bond and 28# (common color copy paper.)
24# bond = 60# text
28# bond = 70# text
32# bond = 80# text
Bulk
Description of a paper's thickness relative to its weight.
Case bound
Hardback book made with stiff outer covers. Cases are usually covered with cloth, vinyl or leather.
Cast coated
A coated paper with a high gloss reflective finish is termed "cast coated."
Cover Paper
Cover paper weight is determined by weighing 500 20”x26” sheets of cover grade paper.
To put it another way, the "basis size" for cover paper is 20" x 26"
Today cover weights vary widely, from 60 lb cover on the light side (a light card stock) to 140 lb cover on the high end.
Color copiers and color laser printers an typically print up to either 80 lb cover or 100 lb cover depending on the model. 80 lb cover is a common weight for business cards and post cards, with 100 lb usually viewed as slightly nicer for higher end cards.
Flood
To cover 100% of a printed page with ink, or plastic, UV, aqueous, or varnish coating.
(as opposed to spot coating where only a specific design area is coated.)
Front trim
Trim used for magazines and booklets with multiple folded, inserted signatures in order to create an even edge; must be accounted for in layout stage.
Full ink coverage
Smallest quantity of ink that can completely cover the surface of a particular stock with no visible gaps. In offset printing, full ink coverage for smooth coated art paper is 1.5 to 2 gsm, and for uncoated papers around 3 gsm.
Gang Printing
Gang printing refers to printing more than one job on the same sheet of paper.
Instead of printing one brochure or 11x17 color sheet per plate and small sheet of paper for example, gang printing allows the press to run the largest sheet possible by placing multiple jobs together on the same plate and sheet.
Gang printing is commonly used by brochure, business card, and catalog sheet discount printers and internet printers now and has been a large aspect of reduced printing prices in modern times for such commodity items.
The advantage of gang printing is a great cost reduction due to reduced waste of plates, paper, reduced changeover time due to less plate changes, and the ability to utilizing the most economical sheet size.
The disadvantage of gang printing is that on-press adjustments cannot be made to maximize any specific job or adjust that job for press or stock variations after the plates have been made since there are multiple jobs per sheet. Depending on how jobs are ganged, this may have virtually no drawback in quality or a drawback small enough that most customers do not mind and choose this method for lower costs for commodity items such as postcards.
Gray Component Replacement (GCR)
Gray Component Replacement, abbreviated GCR, is a technique for replacing gray tones otherwise made from yellow, cyan and magenta separations instead with black ink.
Advantages of GCR include:
• Black ink can be less costly than CMY inks.
• Resulting output is less susceptible to changes and shifts since you are not so heavily relying on the balance as much C, M, and Y.
• Brighter colors can sometimes be obtained on lower grade papers through the use of GCR.
Disadvantages of GCR include:
• GCR may reduce the ability to adjust some colors.
GCR is also termed "achromatic color removal."
Grippers
Metal fingers on a printing press that hold the paper as it passes through the press.
Depending on the press design a sheet may go through several gripper changes from printing unit to printing unit.
One must allow for a gripper margin inset from the edge of the sheet (The "Gripper margin" of a given press is the unprintable area of the page where the printing press grippers come in contact with the paper.)
Hexachrome
Pantone developed solution to the color color gamut limitations of CMYK process printing. Hexachrome printing comes closer to the RGB gamut by adding orange and green inks in additon to cyan, magenta, yellow, and black.
Hickey
A hickey is a spot or printing imperfection most visible in areas of heavy ink coverage. Hickeys are caused by dirt on the plate or blanket.
A Hickey is also called a bulls eye or fish eye.
Paper weight conversion
[h3]Text (Basis 25 x 38)[/h3]
Code:
Text Bond Cover Index GSM
40 16 21 33 60
50 20 27 41 74
60 24 32 49 89
70 28 38 57 104
80 31 43 66 118
90 35 48 74 133
100 39 54 82 148
[h3]Cover (Basis 20 x 26)[/h3]
Code:
Cover Bond Index Text GSM ~C1S PT
50 36 75 91 135
60 43 90 110 162
65 47 97 119 176 8pt
80 58 120 146 216 10pt
90 65 135 164 243 12pt
100 72 150 183 270 14pt
110 79 165 201 297
120 87 180 220 324 16pt
[h3]Bond (Basis 17 x 22)[/h3]
Code:
Bond Cover Index Text GSM
16 22 33 41 60
20 28 42 51 75
24 33 50 61 90
28 39 59 71 105
32 45 67 81 120
36 50 75 81 135
[h3]Index (Basis 25-1/2 x 30-1/2)[/h3]
Code:
Index Bond Cover Text GSM
90 43 60 110 163
110 53 74 134 199
140 67 93 171 253
170 82 114 208 307
Perfect Bound (Pefect Bind)
An adhesive is applied to the spine of collated and gathered pages. A cover is then attached. Perfect bound publications have rectangular backbones.
Perfect Bound is also known as adhesive bind, cutback bind, glue bind, paper bind, patent bind, perfecting bind, soft bind and soft cover bind.
Plus Cover
A paginated document (booklet, magazine, catalog, or thin book) that has its cover printed on a different type of paper than the interior pages.
PUR binding
Binding method for books and brochures which uses polyurethane adhesive applied at high temperature which then hardens as it cools. PUR binding is a high-quality binding method, ideal for high-use books and difficult papers.
Register (registration)
The degree to which printed colors or images are accurately positioned in respect to alignment and contiguity with other colors or runs through the press.
The registration determines the clarity of process color, and whether gaps appear or alignment is correct on multi-spot-color or multiple-pass printing.
If running more than one pass through the press (e.g. 2-sided or multi-color or process color on a 1- or 2- color press) the feeding of the press is the first place where registration is critical.
If running a 2- or 4- color press registration between units can be adjusted as well as skew on the fly to achieve perfect registration.
Saddle Stitch
Binding printed pages with two or three staples through a centerfold.
Commonly 11 x 17 or 12 x 18 sheets are bound by saddle-stitching with two staples through the center and then folding to create a finished booklet, large brochure, or magazine. 8.5 x 11 sheets are commonly saddle-stitched to create programs. And smaller 7" x 8.5" or similar-sized sheets are saddle-stitched to create multipage brochures or small booklets that fit in a rack.
Self Cover
A paginated document (booklet, magazine, catalog, book) that has its cover and inside pages printed on the same type of paper.
Set off
Accidental transfer of printed image from one sheet to the back of another.
Signature
A print sheet of printed pages which is folded and cut to become a part of a bound book or publication. A signature is often a group of 16, 24, 32 or 48 pages.
Text Paper
Text paper weight is determined by weighing 500 25”x38” sheets of text grade paper.
The "basis size" for text weight paper is 25" x 38"
Text paper is used for the inside pages of books and brochures. Common gloss trifold brochures for example are printed on 80# (inxpensive brochures) or 100# text (most common.)
UV coating
A Liquid laminate bonded and cured to the print with ultraviolet light. Environmentally friendly.
In general, UV coating is slightly more glossy than an Aqueous Coating.
Varnish
Clear liquid applied to printed surfaces for looks and protection. Printing varnish can be run like an ink in offset and other presses. It has a similar composition to ink, but lacks color pigment.
UV coating is generally preferred for high gloss. Varnish can add special effects such as a rich satin feel for special projects.
Web Press
A web press is a printing press that prints on continuous rolls of paper or other substrates. These rolls of paper are called webs. Web presses are typically used for very high volume printing including magazines and newspapers. Web presses are much faster than most sheet-fed presses, can often print both sides at once with a reversing bar setup, and produce cut sheets by slicing the output inline. Newspaper web presses are often several floors high.
Heat-set web presses use heat to set the ink.
Cold-set web presses do not use heat to set the ink and typically handle lower volume printing than heat-set presses.
