Graphics File Formats Demystified

Ever wonder when to use what file format and why a printer will not output from a .gif and a web designer cannot use your .eps?

Here is a listing and explanation of common files and the common uses of each:

First off, to fully understand the differences there are 2 terms that need to be defined; Vector graphics and Raster graphics.

A vector graphic is any graphic that is based off of math which in turn makes vector graphics resolution independent. What all of this printer babble means to you is that if you are using a vector graphic, you can stretch it or enlarge it to any size imaginable and it will still output nice and sharp because the graphic just recalculates the math. Another advantage of a math based graphic is small file sizes.

A raster graphic is a totally different story. Raster graphics are based off of pixels which are basically small chunks of information. For this reason, raster graphics are resolution dependent which means that there is a set amount of information contained in the graphic. If you enlarge the graphic, no real new information is created; which is the reason you see pixels and graininess in printed graphics that do not have enough resolution.

.ai – This is Adobe Illustrator’s native file format. Adobe Illustrator is the most popular vector graphics creation program and .ai files support layers. If your designer is using other Adobe programs for print and/or web design (such as Indesign CS4, Dreamweaver CS4 and/or Flash CS4) .ai files can be imported directly into those programs which makes this a good, high quality file format for your logos for use in print or on the web. Just be sure that that you convert all of your type to curves beforehand. Also, please note that in the final code that is uploaded to your webserver, an ai will be converted to a .jpeg or .gif by Dreamweaver.

.eps – This is also a vector file format and it stands for encapsulated postscript. Postscript is a computer language made to send to output devices such as printers, imagers etc. This is a high quality file format for print and mainly used for logos and similar graphics. Unfortunately, postscript does not display on your computer monitor very accurately so an eps is not a good choice for web graphics. Please note that this is not to be confused with a Photoshop eps which is a raster file format and not vector based.

.tiff – This is the preferred raster file format for printing. A .tiff is preferred for printing because it is considered a lossless file format which means there is not a compression system applied to the graphic that throws away your precious data upon saving and/or opening. Basically, all of the original information captured by the native device is maintained and preserved unless purposely edited. However, because of this, .tiffs will often have large file sizes which makes it a poor choice for use on the web which prefers optimized images with the smallest file sizes possible. Tiffs also support layers.

.jpeg – This is considered a lossy raster file format which means, you guessed it, it applies a compression to graphics that does throw away your data upon saving. Some images are high enough quality that throwing away some original data will not make a visual difference especially with today’s high resolution native capture devices. However, on images that you want or need to preserve all of the data possible and get the best quality out of, this is not a good choice. We can output files with placed jpegs with no issue, however do keep in mind that every time a jpeg is opened in a program, edited and saved it throws away data. This quality makes jpegs file sizes a lot smaller than .tiffs which in turn makes it a preferred file format for use on the web.

.gif – This is considered a lossy raster file format just like the jpeg. A gif can only have a maximum of 256 colors which makes is a low quality image file format that is not acceptable for use in print. Gif files are popular for use on the web due to their ability to display simple images well  with very small file sizes. Gifs can also contain simple animations and transparency.

Exporting a Print ready PDF from Quark 8

August 5, 2009 by Brenda Bell · 2 Comments
Filed under: Design, Educational, Preflighting, Prepress 

The procedure described below applies to QuarkXpress 8 for Mac. Other versions of the program work in a similar fashion.

Make sure you’ve saved your file before attempting to create a PDF. First, select the Export option in the File Menu:

A window similar to the one below appears:

Choose a destination for your PDF document, select PDF/X-1a: 2001 as your pdf style, then click the Options button to access settings in the PDF Export dialog box. We recommend using the preset designated PDF/X-1a: 2001 because this is a PDF standard that has been put together specifically for print PDFs.

An additional dialog box opens, which is filled with export settings. In the color section (shown in the above), make sure you create a composite PDF and specify to your job specs: CMYK, CYMK +spot, B&W, Grayscale or As Is if your
project is printing in just spot colors.

Next you will want to add crop marks and bleeds as shown in the following two screen shots:

Click the OK button. You will be returned to the “Export as PDF” window.

Click “Save” to create the PDF

Exporting a Print ready PDF from Indesign CS4

July 31, 2009 by Brenda Bell · 4 Comments
Filed under: Design, Educational, Preflighting, Prepress 

The settings shown here apply to InDesign CS4 for Mac. Other versions of the program work in a similar fashion.

Use the Adobe PDF Presets in the File Menu to access PDF export (as seen below). As always, be sure you have saved your file first. The presets range from Monitor proofing to PDF/X-certified settings. We recommend using the preset designated PDF/X-1a: 2001 (or PDF/X-4a: 2008; see edit at the bottom following this article). This is a pdf standard that has been put together specifically for print pdfs. If you’re using an earlier version (Pre CS) of InDesign (v1 or 2), X-1a:2001 is not offered, so choose the “Press” preset instead.

InDesign will then ask you for a file name and where you would like to save the pdf in a window like the one shown below. Enter the information and click the “Save” button:

After clicking the “Save” button, you will see a window appear like the one below:

Click the Marks and Bleeds section. Crop marks are often necessary when outputting your printed piece, so they should be included on all of your PDFs. Remember that if your source document has bleeds, it is critical to create a minimum 1/8” bleed in the document itself before creating your PDF.

Set your marks and bleeds as shown above.

Please note: The Preset designation changes automatically to “modified” when any of the settings are changed. Changing crop settings in itself is not a violation of the PDF/X-1a standard, so you may proceed with the “modified” setting after doing so.

The Output window will allow you to specify the color mode for your PDF. By clicking the Ink Manager button you’ll see which colors you’ve used in your file.

This feature allow you a final opportunity to determine if color has been applied correctly throughout the document and convert colors to 4-color process if necessary, without having to edit the colors in the document’s color swatch list. Click the OK button when you’re satisfied that all of the ink colors are correct.

IMPORTANT TIP: Do not select any security features in the Security tab. Doing so will prevent your PDF from being processed by our RIP. Password protection isn’t allowed under the PDF/X-1a specifi cation. Leave all of the checkboxes unchecked.

When you are satisfied that all PDF export settings are correct, click the “Export” button to make your PDF:

Edit 8/10/09: As mentioned in the comments below, you could select the X-4a: 2008 standard instead of X-1a:2001 and make the same adjustments as specified above. X-4a: 2008 is a newer revision of the X-1a standard which supports transparency better than the 2001 revision. However, it does allow RGB images, where as X-1a:2001 does not, so be sure to convert all of your images to CMYK before making the pdf, because it will not alert you that you are including RGB images.

What is bleed and why do I need it?

July 2, 2009 by Brenda Bell · 3 Comments
Filed under: Design, Educational, Finishing, Preflighting, Prepress 

In printing terms “bleed” is referred to as a place or places where image on the finished piece is intended to go all of the way to very edge of the sheet. In order to accomplish this effect, we need to have a little extra image beyond where the final cut is supposed to be made. Standard bleeds are 1/8th of an inch (.125″). Cropmarks (as shown in the image above) show our bindery where the cut needs to be made. The image beyond the cropmarks is considered the bleed.

Why we need bleeds is simple. While our computerized guillotine cutters are precise, when cutting large stacks of sheets, there is a very slight variance, meaning that we could set our cutter to cut right on the very edge of the image of the top sheet, but when the blade goes through the stack it may vary slightly leaving a white line on the bottom sheets, which would totally ruin your intended effect! Bleed ensures that there are no white lines and that your print project turns out as you intended and looking it’s best.

So, what does this mean to you as a designer? This means that, unlike your web projects, on your print projects you need to plan for bleed in your file when placing images and creating graphics by making sure you have enough image extend past the edge of your document. Indesign and Quark make planning for bleed easy by either setting your bleed margins or dragging guides yourself.

Exporting a Print ready PDF from PageMaker 7

June 10, 2009 by Brenda Bell · Leave a Comment
Filed under: Design, Educational, Preflighting, Prepress 

Here is a step by step guide on how to provide a print ready pdf from Adobe PageMaker 7. These screen shots were captured on a Mac, but Windows based computers should be similar. Please note that Adobe has replaced PageMaker with Adobe Indesign, so there will be no more updates to PageMaker after Version 7. We suggest that you upgrade to a more recent page layout program such as Indesign or Quark.

To begin, we will use the Export option in the File menu to access PDF export.

PageMaker-Image-1

The window shown below appears. PageMaker presets range from Monitor Proofing to Press. Using the “Press” preset is sufficient in the absence of “PDF/X-1a”.
PageMaker-Image-2

After choosing an export preset, click the “Export” button:PageMaker-Image-3

You will then be prompted to specify a filename and destination for your PDF file. Click “Save” to create the PDF:
PageMaker-Image-4

Tips for Submitting a Print Project

There are several simple guidelines that designers and file submitters can follow to avoid unnecessary prepress charges and project delays.

To ensure a file outputs correctly and consistently it is helpful to have the following:

  • The native art file (sometimes called layout file). This is the file that you would produce in a layout program such as Indesign or Quark.
  • All support files. A support file is anything brought into the layout program, such as an image. When you import a file (like an image), the layout program does not place the entire image; it only places a low-resolution preview and creates a link to the actual file. This means if the support file that is referenced in the layout file is not provided, we cannot output that image. Also be sure to update all of your links before submitting files for printing.
  • All fonts. Due to so many different variations and versions of fonts, it is best to have the font used to create the layout to ensure that your type does not re-flow and otherwise look different that intended. Also, it is worth noting not to use the italic and bold buttons within programs. Use the Italic and Bold versions of the actual font.
  • Lasers or a pdf of the file that you are sending us so we can have something to reference to ensure your file outputs the way you intended.

or….

  • A press quality pdf (such as a pdf built to the x1a-2001 standard) with bleeds

Providing us with all of the types of files is very easy these days with built in features in common layout applications. With the click of a mouse, these features will copy all the necessary files into a folder for you.

  • In Indesign this feature is called Package. Package is located under File > Package.
  • In Quark this feature is called Collect for Output. Collect is located under File > Collect for Output
  • In other programs such as Illustrator, Freehand, CorelDraw etc. the files linked in the layout program and the fonts will have to be tracked down and put in a folder manually.

Here are some other guidelines that will help your digital files not only become a printed reality, but look their best while staying on budget and on schedule.

  • Make sure all images are 250 – 300 dpi when placed at 100%
  • Make sure all images are converted to CMYK
  • Build files to final size and in reader’s spreads. This means if your intended product is 5×8, make the page size in your layout 5×8. If the project includes bleeds (where ink runs off the edge of the paper), extend your images or color 1/8 of an inch beyond the edge of the page where bleeds are intended. If your file is built in printer’s spreads, please inform us so that we can make sure your project is imposed properly.