ASK ANDY




PRINTER'S SPREADS



Since last month I've had several emails, all with questions relating to desktop publishing and pre-press terms.

Q. What does "2-up printer's spread" mean?

A. There's two parts to this -- first the '2-up' then the 'printers spreads'. When printing on a printing press, often because the paper sizes can be much larger than with desktop printers, or the paper may be on a continuous roll, many more pages can be printed onto a single sheet. Rather than print each actual book or magazine page on a single sheet, many pages can be grouped together to print as many pages as possible onto the paper in one pass.

The pages have to be arranged so that when the pages are cropped and folded the pages actually make up the proper reading order and this is where the '2-up' term comes from.

The 2-up means to print two pages onto a single sheet of paper, side by side. So, with a sheet of A4 paper (210 * 297mm) you could print 2 pages from say, a 110 * 110mm document, 2-up on a landscape A4 sheet.

There are also other sizes available, such as 4, 6, 9, and 16-up. In those cases, the pages can be side by side, and in rows as follows (each number represents a page):
2-up:
1, 2
4-up:
1, 2
3, 4
6-up:
1, 2, 3
4, 5, 6
16-up:
1, 2, 3, 4
5, 6, 7, 8
9, 10, 11, 12
13, 14, 15, 16

This means you can print several pages to a larger single sheet, then crop the sheet down to the page sizes -- so you may get 6 actual pages to each printed sheet. The 'printer spreads' refers to the order in which the actual pages appear on paper. In a page layout program such as QuarkXPress, as you create a document, the pages appear in the order you would read them, page 1, then 2, 3, 4 and so on - this is called 'reader spreads'. However, when you print them say 4-up or 2-up, the order they print had to suit the booklet or book when the pages are assembled.

Imagine an 8 page booklet -- this would be made from 2 sheets of paper, each folded in the middle, and printed on both sides of the paper. For the pages to fall into the correct order, page 1 (the cover) would have to print side by side to page 8 (back cover). Page 2 would side page 7, page 6 would side page 3, and page 4 would side against page 5.

So, the readers spreads are:
    1
2, 3
4, 5
6, 7
8 
But the printers spreads for this (if printed 2-up) would be:
8, 1
2, 7
6, 3
4, 5

So when it's printed with these printer spreads, page 8 is printed side by side with page 1, page 2 with 7, page 6 with 3 and page 4 with 5 --so that when the pages are cropped, folded and binded they will be in the correct order.

This whole process of arranging the maximum number of pages to fit onto a single sheet on the press (to get as many printed in one go as possible) and to create the printer spreads is known as Imposition.

This can get mightily complicated, when dealing with say 16-up printing and long book documents! (I wouldn't even like to think about 32-up, 700 pages!!). Fortunately, there are impostition packages available that automatically create the printers spreads etc.

Q. OPI stands for Open Prepress Interface but what does that mean?

A. This is a system to speed up areas of pre-press and preparation of files for printing. An example is in scanning and placing images. Imagine you're creating a multipage catalogue with many high resolution images per page. As this could work out as 15Mb per image, and with 2 images per page, there's going to be many Mb's of images. As you create the catalogue, you might only need to position the images on the QuarkXPress or PageMaker page -- you don't need to do anything else with them.

So rather than deal with the large high resolution images, when they are scanned the OPI system will store the large high resolution images in a folder or directory on a network, and also store smaller lower resolution images (much smaller file sizes) in another folder on the network too.

Now, rather than having to work with the slower, larger file size, high resolution images, you can import the low resolution images (and smaller file sizes, and faster too) into the document and will be able to work quicker and with smaller files.

When the document is printed, the OPI system automatically replaces the low resolution images with the high resolution images required for printing. The advantage is that you can work in your page layout program with smaller, quicker files. When ready they are automatically replaced by the high resolution files for printing.

However, you can only use the low-res. images to position on the appropriate pages in the document -- you cannot edit the low res. images in say Photoshop, as they will not be printed -- they are only to indicate on screen where the image will be.

Then again -- another side to this, is that as you work on your catalogue, positioning the low res. images to suit, someone else on the network can be colour correcting and editing the high resolution files that'll be used when printing.

A further example is if you get a service bureau to scan and correct any images for you, which you are going to place into, say, the catalogue example above. Rather than them having to give you many 15Mb files, then can give you the low res. versions, say only 100k each. This means you don't have so many large files to move about and send back to the bureau. When you send the document off to be printed by the bureau, the OPI system automatically replaces the files at printing time (the filenames must match though -- if you rename any of the low res. files, no high res. version will be printed as there'll be no matching filename).

Q. In the manual for QuarkXPress, the instructions for "Save Page as EPS" say for text to be editable, use ASCII and no preview, then any text editor will be able to open the file. However, I couldn't get Quark or Word 7 to work -- then in another section of the manual it says you can't edit a page saved as an EPS? What am I missing?

A. Generally EPSs are not editable in the way a Quark document (or any native document file) is, all you can really do with them is to place them in programs and print them -- you cannot edit elements within them. EPSs are made from PostScript commands, which is just like a computer programming language, but specifically from printing. When you create a EPS, it's really a listing of commands telling the printer when to do etc. So the EPS may have a command that tells the printer to draw a line 6" along, and 1/4" wide. The whole image is made up from all these commands, and when printed, the command listing is literally run like a program -- the output appears on the printer.

What the manual means about using ASCII to allow for editing, is that with a ASCII EPS you can open it into a word processor, and edit the actual PostScript codes and commands. If you do this, you'll only see the command listing, not the actual images or elements themselves. It's just like looking at the source code for a computer program -- if you know the PostScript language, you'd be able to edit elements and change the page -- but you only know if it's worked at printing time (or if you open it into a PostScript Previewer).

If the EPS was saved with binary encoding, all you would see in the word processor would be gibberish, the readable coding being compacted into binary format to keep the file size smaller.

Unless you are really into PostScript language, there's little that can be gained by editing them by editing the raw PostScript commands -- it's definitely not WYSIWYG! (what you see is what you get!).

However, they've given us the option of ASCII EPSs just in case anyone ever needs to open the raw code and make changes using the PostScript commands etc.

Q. I only copied my QuarkXPress document file over to a floppy disk to hand into my instructor at college. However, I didn't copy any of the image files used in the document over to the disk. Will my instructor still be able to see the images in the QuarkXPress document?

A. Yes, the images would still be visible in Quark. When you import a image into XPress, XPress creates it's own preview version to show on screen. When you print, Quark looks on the disk for the higher res. image and prints that, but on screen it uses the preview it created when the image was first imported. This preview image is always stored in the XPress document file by XPress -- so if the instructor opens your document, they'll still see all the images in colour etc. as they'll be viewing the preview versions.

(This is also good for not having to cart around massive images files -- if you only need to position them, import them into XPress, then you can simply work with the preview version from then.)

Q. If I save a page as EPS and then want to bring it into another QuarkXPress document, do I create a picture box and use the "get picture" menu to import the EPS?

A. Exactly -- some places create small newspaper type adverts in QuarkXPress, save them as EPSs, then import many of the EPSs onto a single page to create complete advert sections etc.

Best to save a copy as a Quark doc, before you save as EPS, as you cannot easily edit the EPS, it's good to have a Quark copy as backup if you ever need to edit any of it.

Then again, if the EPSs get deep, i.e. EPS within a EPS within a EPS etc., this can sometimes cause problems -- maybe best not to go to deep with them.

I welcome any comments or DTP and graphic design questions, so please email me at the email address below, and until next month, happy DTP'ing and keep the questions coming in! --Andy

Contact: Andrew.Davidson@onyx.octacon.co.uk




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