GRC 203 Final

binding, imposition, flexography, printing technology, typography

saddle stitch

4 page signatures are nested within in each other then stitched, lays flat, signature 1 = page 1, signature 2 = page 3, signature 3 = page 5

perfect bound

4 page signatures stacked on top of each other, spine grinded, glued, and cover applied, doesn’t lay flat, signature 1 = page 1, signature 2 = page 5, signature 3 = page 9

pagination

how the pages are numbered, changes based on binding

reader spread vs. printer spread

reader spread = pages laid out to mimic how it is actually going to be read (think indesign layout), printer spread = how it needs to be printed based on its binding method

flatwork

no binding/folding required, either one or double sided, can still require finishing like cutting or coating

side guide

usually 4 inches up, allows us to know if page are lined up when stacked (essential for finishing)

color bar

at the top edge of press sheet, tests how color lays down, ink will spread and get on blanket if pushed all the way to edge

text marks and text mark variables

help with identifying press sheet, preferably by page 1, variables programmed into application ($time, $date, $color)

step and repeat

same object placed multiple times, for sheetwise or flatwork

sheetwise imposition

front and back are different, gripper edge is the same, side guide may change, H to H or F to F doesn’t matter

work and turn imposition

sheet turned during second run, same plate used for front and back —> minimizes number of plates used, gripper edge stays constant while side guide changes (vertical axis), each impression generates two signatures when cut, common for book work (front and back covers), increase chance of registration issues b/c side guide is changing

work and tumble imposition

same plate used for front and back, gripper edge changes but side guide remains constant (horizontal axis), can be done in one pass if on a perfecting press

signature lap

intentional overlap of one half of the signature to allow the saddle stitch machine grippers to open it (not for perfect bound), usually 1/4-1/2 inch (depends on equipment)

high folio lap

back pages (higher folio numbers) sticking out

low folio lap

front pages (lower folio numbers) sticking out

you should always use dielines, never ___ cuts for flexo

square

dielines

define where to cut and crease, the shape of the product

things to be aware of when using a nested layout

can’t do big rectangles of color

eyemarks

tells the automated printer where to cut, positioning depends on the job/desired shape

trapping

overlapping adjacent colors to account for misregistration and prevent white leaks

default trap amount

½ pt

three different states of trapping

1. default knockout — top shape prioritized and blocks out color below it

2. trapping light color into the dark

   1. overprint — only for black text, lighter color above

spread

color being pushed outwards into the other (ex: spreading light color into dark color)

choke

color being pushed into, shrunken in (ex: dark color being chocked by the light)

common colors and trapping

process colors that have a value in common do not have to be trapped (ex: if both colors have magenta)

tint reduction (in terms of trapping)

for when the trap color is too strong, always 40%

sliding trap

for gradients, needs to be consistent to prevent detection

cut back (AKA keey-away)

used for rich blacks to prevent messy looking text, cut back/choke CMY so the black misregistration doesn’t leak

metallic and opaque inks for trapping

need to know order of inks on the press to ensure that shape is held

trap value for narrow web

1/64’’ but depends on substrate

trap value for wide web

varies and depends heavily on substrate (ex: substrate being fed in flat —> less registration control —> more trapping needed), corrugate = 1/8th in

type size for trapping

depends on whether its positive or reversed, whether its serif (at least 8 pt) or sans serif

multicolor type and trapping

dominant color should be used to hold text shape (same for knockout), need to prevent bad misregistration especially foreground color getting into knockout

gradients on an electronic file vs. press

go from 100% to 0% vs. 100% to minimum dot % (flexo can’t hold 1-2% dots) — dont use gradients that go all the way to 0% on design file

dot gain considerations

unavoidable but can be compensated for in the design file by lowering tint value, expanded dots print darker, usually at least 10%

bar code considerations

minimum scaling is 80%, maximum is 200%, optimum background is black on white, be mindful of substrate texture and color (can’t use red for code), make sure it’s in picket fence orientation and not ladder

image stagger

helps keep images consistent

why does distortion on flexo printing occur

the outside circumference of the plate wrapped around the cylinder is wider than the inner circumference so it get’s stretched

compensating for flexo distortion

app to calculate how much it needs to be adjusted vertically (never adjusted horizontally)

different types of printed dot shapes

round, euclidian, elliptical, square, novelty/specialty

round dot shape

the most common, dot briding at 75%, non directional —> good for general use

euclidian dot shape

round-square-round dot (50% square), good for shadows, simulates film-based technology, dot bridging at 50% (more noticeable), white peaking through is the substrate not dots

elliptical dot shape

directional, dot bridging split between 40% and 60%, can increase moire w/ fabrics (not ideal for projects like catalogs)

square dot shape

typically seen on letterpress, poor shadow detail, gives illusion of sharpness

novelty/specialty dot shape

custom created depending on production process, beware of additional charges, always consider the project

conventional screening

aka AM (same frequency, diff size), lpi (frequency of the screen) determines dot arrangement — high lpi = smaller dots/grid, low lpi = larger dots/grid, SPACING between dots remains the same, DOT SIZE changes

advantages of conventional/AM screening

smooth and solid tints, easier to image, less dot gain, easy to measure dots (allows for greater quality control)

stochastic screening

aka FM (same size, different frequency), can’t put grid on it — no structure (especially in shadow area), DOT SIZE remains same, SPACING between dots changes

advantages of stochastic/FM screening

increases detail, less chance of moire b/c of random dot pattern (good for clothing catalog)

disadvantages to stochastic/FM screening

harder to image/print, dot bridging gives worming effect, more dot gain

hybrid screening

AM for midtones, FM for highlights and shadows, requires specific RIP that can image it, goes from grid to random

HD screening

adds tiny dots to support highlight dots

screen frequency for conventional/AM screening

measured in lpi, depends on process and substrate, examples: screen print = 45-65 lpi, web-offset = 120-300 lpi

screen frequenc for stochastic/FM screening

measured in microns, usually 10-30, should be slightly longer than the smallest highlight dot that can be reproduced

relationship between screen frequency and shades of gray

screen frequency increases —> shades of gray decrease, screen frequency decreases —> shades of gray increase

minimum shades of gray for best output quality

256

formula for calculating shades of gray at different output resolutions and screen frequencies

(output resolution/screen frequency)² + 1

screen angles

the angle each color in conventional/AM screening is screened at, creates rosette pattern, changes depending on printer

rational screen angle

clean number like 45, 90

irrational screen angle

unclean number like 74.99, minimizes moire patterns, for flexo not offset

principles for repeating screen angles

will have to reuse a CMYK angle for every extra spot color, reusing yellow’s angle should be the last resort, blue color: yellow angle, green color: magenta, red color: cyan

computer to plate (CTP) printing

offset, flexo, screen, gravure

computer to press

digital

postscript

used to send to printer on desktop, has to be interpreted by RIP (can’t just open to view, more limited than PDF)

PDF preset principles

never use default adobe ones b/c they use JPEG compression, include bookmarks and hyperlinks for web, compression should always be none or ZIP, check downsampling to reduce file size, check Crop Image Data to Frame, generally only need trim marks (no bleed, color bars, etc.), dont color convert in application do in acrobat

history of type

pictographs (cave paintings) —> ideographs (hieroglyphics) where symbols = ideas —> phonetic (alphabet) where symbols = sounds

linotype

developed after Gutenberg, sets one whole line at a time —> increase productivity, hot type

photo typesetting

use film to create plates — light projected thru negative image of type, leading, tracking, and kearning easier, cold type

electronic typesetting

do at home, 300 dpi, only other alternative at the time of development was the typewriter

measuring type

from the ascender to descender (why fonts w/ larger ascenders and descenders will naturally look smaller), 1 in = 72 pts = 6 picas, 1 pica = 12 pts, 1 pt = 1/72 in, inches > picas > pts

kerning

space between individual characters

monospace

all characters are equal width

proportional

all characters are unique width

ligature

connecting two characters in a way that they behave as a single character, common pairings include fl, fi, ff, ffi, ffl, adjust (can add discretionary) via Window > Type > Open Type

tracking

spacing for whole line of text

leading

space from baseline to baseline (between lines of text), auto leading (default in illustrator) = 120% of font pt (font = 12 pt, leading = 17.4), set solid = leading same pt as font, manual = custom

space after

prevents double return between paragraphs

space before

applied to headings to get same effect as space after

justified type

both edges of text column align, creates rivres

line length

should be around 9-10 words (50-56 characters) for optimal readability

quotation marks

only for letters, use prime marks for numbers (like when referring to inches)

hanging indent

for list, 2nd line should align with first, cmd + back slash

font technologies

type 1, true type, open type

post script type 1

2 fonts work together — screen font to preview on screen and printer/post-script font to actually be printed on output device, not cross-platform

true type

single file does everything, not cross platform

open type

single file, extended character st (more glyphs), cross-platform (can use across apple + windows), modern industry standard

multiple master fonts

shows up as MM in font dialog box, customizable Type 1, characters described in terms of variable design axis

CID

character identifier, multi-byte Type 1 to support eastern character sets, large file containing all character outlines (can cause output issues)

prepress font issues

not all fonts created equally (can have same name on a platform but be altered slightly), font substitution typically caused by missing fonts at output, stylized text for CTP, 4C text and rich black

prevent font substitution

supply fonts, embed in the PDF, set preflight to check for fonts not included, beware of spaces, numbers, and punctuation

text overflow

usually caused by font substitution

variable type

adjust weight and width within application’s character panel (supported by Indesign 2020 and illustrator 2019 and beyond)

font legality

protected by copyright (copying files usually prohibited), can embed into output file, may be able to just view and not print without license

embedded font subset

specific characters only used in the actual document are embedded, minimizes file size but makes editing more difficult later on

overprint

two colors overlapping to create a third color

what method of printing is flexography

direct

most common file formats for flexo

illustrator and adobe pdf

dielines should always be what type of layer

overprint (not knockout)

type of color commonly used for flexo

spot

what does image stagger do

helps keep images consistent, prevent issues with print quality