Prepress

 

 

Desktop Publishing

Technique of using a personal computer to design images and pages, and
assemble type and graphics, then using a platesetter to output the assembled
pages onto the printing plate. This process is used to design products ranging
from small ads to entire books.

Typesetting

Typesetting is the process of presenting type in a graphic form; on paper or some other medium. Traditionally, typesetting was done by compositors working by hand and later machines to produce formatted pages of information. Today typesetting is mainly done on computers using desktop publishing software such as Adobe InDesign or QuarkXPress. Typesetting is often taken from handwritten copy, formatted on a computer and sent through the digital workflow to produce plates for the presses.

Example

You give us this

We give you this

Clients can also provide print companies with files they have formatted on their own computers.

After slaving over a hot computer for hours, you finally have your file ready to submit, or do you? There are many tips that will make your files' trip through prepress quicker and ensure the highest quality finished product.

The most common problem with client supplied files is missing information. Not everybody has your fonts! A font file contains information about the style, size, appearance, kerning, tracking, and leading of your type, when these files are missing a generic font file is substituted. This can result in missing characters, unevenly spaced words, reflow, and other copy chaos.

Many programs allow you to link graphic elements to your document. It is important to include the linked files used, as missing links result in poor quality (72 dpi) or missing graphics in your job. Using vector, or high resolution (300 dpi+) graphics will also increase the professionalism of your job. More and more programs are also offering a "collect for output" or "package" option which easily collects the necessary files for you.

Do elements in your file run to the edge of the page? If so, you'll need to add bleed. Bleed is a term that refers to printing that goes beyond the edge of the sheet after trimming. The bleed is the part of your document that gives the printer that small amount of space to move around paper and bindery inconsistencies. Bleeds are generally 1/8 of an inch from where the cut is to be made. Adding bleed to your files ensures that no white space is left between items that run to the edge of the page and where the page is actually trimmed.

Some other essential things to check:

  • Are the colours used in the file correct? Make sure that if you are using spot colours they are consistent throughout your file and that your palette does not include colours that you are not using. This will help to avoid plates being output with incorrect or empty separations. Some applications such as Microsoft Word are not designed to output to print, so the only option is RGB. Don't worry your printer will be able to convert your document to CMYK, but there may be colour shifts.
  • Does the page size correspond with the dimensions of your finished job? If not, inserting appropriate crop marks will ensure your job will be trimmed where you want it to be.
  • Layers, if you are using them, should be visible and in the correct order. Layers not being used in your document should be deleted as they can contain unnecessary elements and increase your file size.
  • Is your hard copy consistent with your file? Prepress operators often refer to hard copy provided by clients to ensure the job is progressing the way it should, sometimes changes to the file are not reflected in the hard copy. This can lead to conflicting information and cause delays in the processing of your job.
  • Do not use "hairline" for rules or strokes in your document. Hairline by definition is the smallest line that a printer can print. On a ink jet or laser printer the line may look good, but on a high resolution imagesetter a hairline will not be visible. The finest line our offset presses can hold is about 0.25 point.

Make sure that you have provided everything necessary…

  • Fonts used in your publication.
  • All the files containing images, illustrations, or other placed graphics.
  • All your program data files.

If you are submitting PDF Files, the files must be prepared correctly. PDF files need to be created to have all fonts embedded and all images not downsampled to less than 300 dpi. For more on how to prepare your PDFs to print at Priority Printing, see Transfer Files.

Make sure that you have checked the proper options when printing to file…

  • Have you reset the enlargement/reduction ratio to 100%?
  • Did you disable the thumbnail printing option?
  • Do you have print as composite selected?
  • Are the appropriate options checked for printing graphics and images?
  • Did you check the option: "Include downloadable fonts"?
  • Have you indicated how you want colour separations to be printed?
  • Have you indicated custom screen angles and lines per inch (if you want these features)?
  • Did you disable the tiling feature (if you were proofing large pages on an office laser printer)?
  • Did you reset the page range to all and check that include blank pages is on?

Always provide your service bureau with an actual-size, hard copy proof, or PDF soft proof of your project. This will help your service provider identify problems, such as missing fonts or graphics.

Provide necessary fonts

Before submitting a file to a service bureau, make sure that you have collected all the fonts used in your document as well as all the fonts used within placed graphics in your document. Specify both the typeface foundry (such as Adobe, Bitstream, or Monotype) as well as the name of the typeface (such as Caslon or Garamond).

If the service bureau doesn't have the appropriate fonts, you can either submit your work as Encapsulated PostScript Files with the fonts converted to outlines or curves, or provide copies of the fonts with the understanding that you are providing the printer fonts for use on that job only.

You should provide printer and screen fonts for each style variation used in your publication such as Times Italic, Times Bold, and Times Bold Italic, as well as Times Roman, and so on.

You can avoid a lot of potential problems by sticking to name-brand fonts. Avoid sending service bureaus projects created using off-brand or "699 fonts for $6.99". Stick to quality fonts from brand name vendors.

Avoid "hidden" fonts…

If you have extensively reformatted your document, especially if you have tried several typefaces, some "hidden" fonts may remain. There may be leftover spaces originally created with the discarded typeface. When this occurs, the workflow is likely to waste time searching for the font and informing the service bureau operator that a font is missing. Under certain conditions, line endings and page breaks might also change. These problems can be avoided by making the proper use of styles and by using the various utilities available to identify each of the fonts used in a project before it leaves your computer.

Avoid overly large files…

Compress your files by using File Save As before submitting files to a service bureau. Large files are more prone to crashes and corruption than smaller, more manageable files.

If sending files by email or FTP, compressing your files before submitting them can decrease upload and download times. Compressed files are less susceptible to corruption from being transferred over the internet.

Trapping…

Is creating hairline overlaps to ensure that where different colours register together no gaps will show. Today, most trapping is done automatically at some point in your files' journey through the digital workflow. Automatic trapping is capable of trapping abutted, solid objects, screens, gradients, and images. Contact your service provider to see what their trapping requirements are before trapping your file.

Graphic Formats…

Graphic data is stored in a variety of ways of storing images called formats, for integration in other application programs. Three of the most popular formats are:

TAGGED IMAGE FILE FORMAT (TIFF)

Tagged Image File Format is the most flexible and reliable method for storing bit-mapped images in various resolutions, gray levels and colours. It cannot store object-oriented images. TIFF was created specifically for storing gray-scale data and it is a standard format for scanned photographs. TIFF is now considered a standard graphics format, and is called "TIFF/IT"

POSTSCRIPT FILE (PS)

A PostScript file is a purely coded text-base description of an image, without the displayable screen image the EPS offers. In many applications you can create a PostScript file and then (if you know PostScript coding) open the file with any word processor and modify typographic and positioning information.

With a PostScript file, you do not need the originating program to print the file as all of the font and image data is contained within the file. The PostScript file can be sent to a PostScript printer with a download utility. There is no preview image and the graphic essentially loses all editability.

ENCAPSULATED POSTSCRIPT (EPS)

Encapsulated PostScript is a popular format for storing vector or object oriented artwork. It can also store bitmaps. An EPS file in ASCII format usually contains two versions of the graphic. The main image is a resolution-independent PostScript description for printing on a PostScript device. The second, optional image is a low-resolution, bit-mapped preview that can be displayed on-screen. This double-image scheme enables page layout programs to import, crop and scale high-quality EPS graphics while using the screen version for the user.

EPS files can be resized, distorted or cropped and most programs that perform colour separations accept and colour separate them.

PORTABLE DOCUMENT FILE (PDF)

PDF is a file format created by Adobe Systems in 1993, it is supported by many operating systems and includes the text, fonts, images, and 2-D vector graphics that make up the file. Often PDF's use a part of the postscript language to generate the layout and graphic elements. Exciting improvements are continually being made to PDF. The format is now capable of maintaining live transparency and layer editing capabilities which were previously only available to the programs from which PDF's were created.

Proofreading is done at several stages in the typesetting process. Initially a proof is read by a proofing department and once it is completed to their satisfaction, sent to you, the customer. It is imperative that proofs are read carefully and thoroughly.

How to proof:

1. Look to see if the general layout is correct. (ie. functional or appealing to the eye)

2. Read carefully looking for spelling or punctuation errors. Computer software programs cannot be relied upon to spell check for a number of reasons. They cannot recognize proper names, they cannot check for comprehension (ie: hen typed instead of then) and not all programs have spell check features.

3. Read through for comprehension. Does everything make sense?

Proofreaders' Marks

The proofreaders' marks shown on the following pages are standard and should be familiar to everyone working with type. It is important to use these accepted signs, rather than others which will not be understood by the typesetter. Marking changes with a coloured pen or pencil enables the typesetter to see the corrections more easily.

When marking changes to a proof, it is extremely important to make sure that the changes are legible and that there is enough information regarding the changes to assure they will be done to your satisfaction.

You can change the look of a printed piece by changing the point size and fonts. Refer to the following charts for samples of type sizes and typestyles.

Line Weights

Commonly Used Type Sizes

Some Common Typestyles


 

Proofs come in many forms, depending on the goals and complexity of the job.

Type Proofs — Output from a computer printer or image setter and also called galley proofs or page proofs, depending on the system used and what is considered camera-ready-copy.

Photocopies — Proofs for quick printing jobs. Photocopies of mechanicals may simulate the final product of a black only job.

Laser Prints & Thermal Proofs — Proofs of pages assembled in desktop publishing systems, but not yet transferred for high-resolution output.

Digital Proofs — A digital proof is a colour prepress proofing method where a job is printed from the digital file using ink jet, colour laser, dye sublimation, or thermal wax print technologies (now commonly used as colour managed contact proofs) to give a good approximation of what the final printed piece will look like.

Soft Proofs — A proof that is generally viewed on calibrated and profiled colour accurate monitors. A PDF used for proofing purposes would be a soft proof.

Integral Proofs — For four colour process jobs. Integral proofs show register of separations and show how colours will reproduce on press. They are known by several brand names, such as Agfaproof, Cromalin, Fujiproof, Matchprint, Pressmatch, and Signature.

Press Proofs — For jobs where the customer and/or printer want to ensure that all quality standards have been met. Press proofs show the job running on the press. Any changes to the job at this time, or delays in coming to a press proof are chargeable.

Bindery Proofs — For jobs involving complex bindery procedures. They confirm correct folding, gathering, and trimming. Bindery proofs are also known as book proofs.

Output printers of all kinds have three basic functions: (1) final copy for reproduction — the output will be used to produce a plate for printing; (2) proofing — the output will be used for review and approval; (3) demand printing — the output will be used as the final end product of users. This usually results from a higher speed laser printer. The quality, speed and other attributes of the printer will be taken into consideration for these purposes.

Impact printers are essentially serial impact printers, which means that they print one character at a time, in sequence. The characters or dots are produced by hitting a number of vertically aligned wires with a hammer. The wires strike a ribbon and the ribbon marks the paper.

Ink jet printers produce images by using liquid inks which are ejected from a printhead either by a pumping action by a piezo electric crystal (drop on demand), or by vapor pressure from a vaporized droplet of ink (thermal ink jet or bubble jet).

Continuous ink jet uses a constant stream of ink which is deflected electrostatically. This is far more complex and costly but can yield extraordinary results, even on plain paper.

Solid ink jet technology uses solid inks which are melted, ejected from a hot printhead and then freeze on contact with paper. This approach offers good quality on plain bond paper.

Laser printers that produce black-and-white images on plain paper have replaced or picked up majority of the workload from line printers, daisy wheel printers, pen plotters, dot matrix printers and some photo-plotting film recorders.

Imagesetters/Platesetters produce images from an electronic file to film, high resolution paper, polyester plates, and aluminum plates.

Line Copy…

Line copy consists of solids, lines, figures and text matter. The image has no gradient tones requiring a halftone screen. Optimal resolution is 1200 dpi.

Halftone…

A single colour continuous tone image scanned, or digitally captured to convert the image into a digital file.

Duotone…

Black and white photograph reproduced using two or more different spot colours that emphasize different tonal values in the original. Duotones are usually printed using black ink and one other ink colour. They can also be printed using two black plates or combinations of any two ink colours. The same technique can be used to create tritones or quadtones.

Colour Separations

Colour originals which are scanned or supplied digitally that are separated into the four primary printing colour components; black, cyan, yellow and magenta.

Four colour process printing…

Technique of printing that uses process colours — black, cyan, yellow and magenta — to simulate full-colour images. Also called colour process printing, full colour printing, and process printing.

Transparencies in their native state are layers of elements with an opacity applied to one or multiple layers allowing bottom elements to show through the top layer.

A transparency is an object attribute applied to elements within your document. It can be applied to images, fills, and strokes and includes effects such as feathering and drop shadows.

A colour created by dots instead of solid ink coverage. Screens appear less dense than solid coverage, thus simulating shading and lighter colours. The best screen ruling for a printing job is determined by the image to be reproduced, the technique used to make the screen, and the press and paper used to produce the final product. A good rule of thumb is a coarse paper, use a coarser screen, a fine paper use a finer screen. Eg. uncoated use 175 line, coated use 200 line or more.



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