Nowadays PDF (Portable Document Format) files are quite common for viewing
pages. Most of the magazines and newspapers send high resolution PDF files to
press for printing. But there are certain checkpoints that need to be taken care
of before sending them.
A PDF file is preferred over an EPS file or a Postscript file because its
size is smaller . For instance a PostScript or an EPS file of a single page of a
magazine with lots of images may take approximately 40-50 MB space, while PDF of
the same page will take only 3-4 MB space. The best part about using a PDF file
is that anybody can open it using the freely available Adobe Reader. Moreover,
while using a PDF file, you don't have to worry about missing fonts, since all
fonts are embedded within the PDF file. In addition, after opening a PDF file in
Adobe Reader you can perform operations such as View, Share, Print, Crop, Add
and Delete pages. You can transfer, open and view these PDF files on any
operating system like PC or MAC without losing important data, fonts, style
sheet or page formatting. Let's see what you should look at before sending a PDF
for final printing.
|
Ready to RIP?
Files that are ready to be sent to press are called as being ready to
RIP(Raster Image Process). The first thing that you should look for is
undesirable white space outside the printing area. If a PDF file has too much of
white space outside the printing area, then its size will be larger and one can
also face problems while printing it. To get rid of this, you need to crop the
file. To remove the additional white spaces, go to Tools >Advanced Editing >Crop
tool. Then select the area you want to keep, press the Enter key and the
undesirable white space area is removed.
After cropping the file if you need to measure the width and height of
printable area, then select the measuring tool from Tools >Measuring >Distance
Tool. This can also be used for measuring specific areas of a document such as a
box, table or picture size, before the final PDF is sent for printing.
There are several instances when you need to insert or delete a few pages
from a PDF file. To do so, open the PDF file, go to 'Document' menu, select
'Insert Pages' option and a new window will open up. In this window, select the
file to be inserted within the existing PDF. After this selection, another
window pops up, in which you can define where to insert new pages. You have two
options, 'Before' and 'After.' Select the one you need and you will have two PDF
files merged into a single one. Remember, there is no way to undo this page
insertion process, so make sure you save a copy of the original PDF file. Apart
from inserting pages, you can also add, delete and rotate the page clockwise or
anti-clockwise.
Use the 'Crop tool' for removing the additional white space outside the printing area |
Creating small-sized PDF for approval
If you want to send the final PDF file through e-mail for approval, you can
reduce the file size. For this, go to 'File' menu and select the 'Reduce file
size' option. A pop up window will appear in which you can select the size
reduction options. In the following window, select the Acrobat compatibility
option as per your requirement, click on 'OK' and you are through.
Is your PDF file printable?
Another important point to be checked is whether the PDF file created by you
is printable or not; since for printing high-resolution PDF file is required.
Also, images and text of the PDF file should be in CMYK color mode. This is very
important as the Offset printing technology supports CMYK color mode only. If
you send your PDF file in any other mode, then software like CTP/Imagesetter
programs may not be able to convert Spot or RGB to CMYK color mode. The
resulting image in such a case will be black and white. So, you need to check
the color mode of the PDF file.
Select the Output Preview option from the Advanced menu for checking the color mode of the PDF file |
To do so, go to Advanced>Output preview and this will show you the color mode
used in the PDF file. The figure on left is showing Spot colors other than CMYK
colors. So, you have to change Spot or RGB colors to CMYK. To do this open the
original file, change the color mode and then create the PDF again. But, if you
don't have the original file, then you have to use other programs like
Illustrator, CorelDraw or Photoshop for converting the color mode of images and
text to CMYK.
The screenshots from left to right, demonstrate the complete process for checking the resolution of images in a PDF file by using the Preflight option |
If resolution of the file is not good then the page will lack visibility. To
check the resolution of a PDF file, 'Preflight' option is available. Go to the
Menu >Advanced >Preflight. Select the 'Preflight' option that opens up the
'Preflight' window. This contains several points, but a few of them are
important for checking the PDF file quality. From the window, select'List images
below 250 ppi.' This will check the resolution of the images and background
colors. If the images are less than 250 ppi, there are chances of low quality
prints. Please change to 'high-resolution image' and send to press for printing.