Pastors and church administrators are on the other end of my phone every day. When I supply a church with final files for a project, I invariably receive a call inquiring about the types of files found on the supplied disc. When Church Graphics.org completes a project, we always try to supply the client with as complete of a file set as possible. The confusion comes when clients can not open certain filetypes on their computers.

In an effort to bring some clarity, I am putting together the following list. It is not meant to be exhaustive; it is only supposed to give explanation to some of the most common types of files we may submit in a graphic file package. The listed items are meant to be practical, and not technical, explanations.

JPEG/JPG: A file with the extension (.jpg) is called a ‘JPEG’ file. This is an image file that can be used in a wide range of applications. When we provide .jpg files to our clients, we usually do so in different resolutions. A web jpeg will have a small file size and be suitable for display on websites, blogs, emails, and the like. A medium resolution jpeg will be useful for desktop publishing programs such as Microsoft Word or Powerpoint. A high resolution jpeg would work well in print layouts and larger format media such as posters or banners.

Jpegs do not support transparency, so if you want a logo do be ‘clear’ instead of having a white rectangle around it, you are going to need a different type of file.

TIFF/TIF: A file with the extension (.tif) is called a ‘TIFF’ file. This filetype retains all of the data in the original or source image. TIFF files will not open on most consumer software. They are mostly recognized by high-end design software such as Photoshop, Indesign, and Quark. As such, these files will mostly be useful to graphic designers that may be assisting you in the future.

Tiff files are able to retain transparency, but they will only be transparent if it is specified at the time the file is saved. A tiff file saved out of Photoshop can retain layers if specified. That means that anyone working on the file in the future could have access to all of the file data that was in the original source file.

EPS: An EPS file (.eps) is a file with data coded to be produced by a professional press. EPS files are often provided for a logo because they are able to retain vector data. Vector images are produced with mathematical code instead of by thousands of tiny color dots. Graphics created with vectors are able to be scaled infinitely without blurriness or loss. Though EPS files can also include pixel (color dot) data, many (if not most of) EPS files will contain clean vector graphics that can be printed on a billboard, or the side of an airplane, or the face of a cliff, without any jagged edges.

If you want to print your logo on a t-shirt or coffee cup, or you want to laser emboss it onto a plaque, or you are trying to produce a three-dimensional version of it for the facade of your building, the professionals assisting you with your project will invariably ask you for an EPS file.

PNG: A PNG file (.png) will often be included in a graphics package because it is one of the few filetypes that is recognized by home/consumer applications like Microsoft Word and Powerpoint that supports transparency. For do-it-yourself flyers and brochures, PNG files let you place your graphic onto any background without the annoying white rectangle border surrounding it. Use a high resolution PNG file for print layouts and reserve the smaller files for use on the web and in email.

PSD: A Photoshop file (.psd) contains all of the original data found in the source artwork file designed by your graphic artist. A PSD file is only openable in Photoshop, though it may be placed into other serious graphic design programs like Illustrator and Indesign. Only professional users with Photoshop installed on their computers will be able to open a PSD file.

INDD: An Indesign file (.indd) contains all of the original data found in the source layout file designed by your graphic artist. An INDD file is only openable in Indesign. Only professional users with Indesign installed on their computers will be able to open an INDD file.

NOTE: INDD files are version specific, which means that a file created in Indesign CS4 will not be openable in Indesign CS3. To make the file available in a previous version, a designer may include an Indesign Exchange file (.inx). This file would be openable in previous software version than the one in which it was created. However, files must be checked carefully when opened in a previous software version because any features of the file specific to the newer software version will be missing and may significantly alter the layout of the graphics and/or type.

AI: An Illustrator file (.ai) contains all of the original data found in the source layout file designed by your graphic artist. An AI file is openable in Illustrator, and may also be opened in other serious vector graphic programs. Only professional users with Illustrator installed on their computers will be able to open an AI file.

NOTE: AI files are version specific. If you have an older version of Illustrator than the person who created the original file, have them save a copy of the file that will be compatible with your version of the software. Files saved for previous versions must be checked carefully when opened because any features of the file specific to the newer software version will be missing and may significantly alter the layout of the graphics and/or type.

In short, everyday users are going to find JPEG and PNG files useful for desktop publishing, presentations, email, blog, and general web use. Graphic artists and other professionals are going to have use for PSD, AI, and INDD files, along with TIFF and EPS files. Professional presses, sign shops, and companies dealing in promotional materials will most often look for EPS files.

The technical aspects of these filetypes are not explored here. This list is only meant to give a practical overview of the assortment of files you may see when you peruse a disc of files provided by a graphic designer. You may run across many other filetypes, but this basic list will arm you with an overview of knowledge. Even if you can not open certain files supplied to you, it is always a good idea to save all files for use by professionals at a later point in time.

Part 2: Image Size and Resolution

Countless times when asking for a logo file, I have been directed to a ministry’s website where I can right-click on an image and save it onto my hard disk for later use. This seems like a logical progression: here is the logo looking crisp and wonderful on the screen, and how much better it is to get the artwork this way than having to dig through years-old discs to find the original file.

In my endless quest to never print another pixilated image, I am writing in order to take a touch of the mystery away from the issue of image sizing and resolution.

Imagine that you want to construct a 12” tall letter ‘A’ from building blocks. You can choose to create your masterpiece out of Lego blocks or Duplo blocks. (Remember Duplo blocks – the big, chunky building toys too large for toddlers to swallow?) You are limited by size (12”), and you want the edge of the letter to be as detailed as possible. You would definitely use Lego blocks instead of Duplos to form the shape of the letter because they are smaller and allow you to include more detail in the sculpture.

Digital images work in this same way. Each image file has two variables, its dimensions, and its pixel density. Two images may have exactly the same dimensions as each other but would yield drastically different print results if their pixel density values were different.

You may have heard someone mention the terms ‘DPI’ or ‘PPI’ (Dots Per Inch / Pixels Per Inch). Referring to image density, the terms relate to the number of dots (or pixels) that can be found in a horizontal or vertical inch of the file.

Let’s say your church logo is a square that generally prints in a 1” x 1” area. If we prepared the file at 10 DPI, it would mean that 10 dots would form each row of graphic data and 10 dots would form each column of graphic data, for a total of 100 dots. Now imagine if I gave you 100 white and black Lego blocks and asked you to build a version of your logo out of them. The result would be pretty jagged.

The relationship between the dimensions of an image and the image density works like any good old-fashioned ratio. If I have an image that is 1” x 1” at 100 DPI, I can change the size to 2” x 2”, and the DPI to 50, and the image would not change quality at all. There still would be 100 dots forming each row of horizontal and each row of vertical information.

Onto the ‘magic’ numbers. If you are designing a piece intended to print, the minimum DPI you want to use is 300. Many professional printing companies will ask for 350, 600, or in some rare cases 1200 DPI files, but for the most part 300 is adequate.

For web design, all that is needed is 72 DPI. This is a major degradation of the image compared to the resolution of print images that are over 4X the size. Why is this?

The information displayed on computer monitors only displays at 72 dpi (in most cases), which is not all that much. If you snuggle up with your display, you will see that most the letters and shapes on display actually have fuzzy edges. This is called anti-aliasing. An alias is a five-dollar word for a little jagged edge that is created when a shape is produced at a low resolution. This sophisticated anti-aliasing process occurs every time you type a single letter in your email program.

Distance is said to be the great healer when it comes to graphic issues, and when you sit a foot or two away from your monitor, what once was fuzzy appears clean and crisp. Don’t be fooled though, the graphic designer who constructed your website took your nice crisp logo and down-sampled it to 72 DPI which will ONLY look good when displayed on-screen.

Printing presses, and even home inkjet printers are capable of producing a much higher volume of dots per square inch. Our eye is much more accepting of low resolution on our screens than it is with any printed material. There is a lot of mind-bending science as to why, but the important thing is to accept that this is true.

Have you ever tried printing a graphics-heavy web page? What was dramatic and lively on the screen becomes a pixilated, jagged, lifeless mess. The DPI issue is one of the major factors in the disappointing printout.

An image down-sampling is a one-way street. An image with a lot of resolution can always be scaled down further. Once the degradation has occurred, the only way to get a larger version is to return to the original file, make another copy and down-sample it to the new desired size.

So next time you wish to have your logo produced on a brochure, don’t go running for your home page, and whatever you do STAY AWAY from the right-click button. Open up the bottom desk drawer and dig out the original source file. You’ll be glad you did.

Part 1: Understanding Bleeds

“This file you sent does not bleed.”

What sounds like a morbid statement from your designer actually refers to an extra bit of ink printed around the edge of your file that will later be trimmed off to give your printed piece a clean ink-to-the-edge aesthetic.

If the final size of a postcard is going to be 8.5” x 5.5” and you don’t want to have a homemade-looking white border around the design, then you will have to build some bleeds around the edge of your piece. Usually 1/8 of an inch (.125”) is adequate, however some printers are more specific about the size of bleed necessary for good output.

The size of the document sent to press becomes 8.75” x 5.75” and should be sent to the printer with instructions that a .125” bleed was included on all four sides and should be trimmed away once printed.

This has bearing on your in-house pieces as well. If a designer is going to be preparing a file for you to print on a color copier in the back room at your church, they will need to know some information from you about that machine before work can begin.

Supposing the piece a designer crafts for you has a largely navy blue background with white (reversed) text. The piece is meant to be a letter, so the finished size is to be 8.5” x 11”. There are two choices:

1) Have the designer build the file with no bleeds. This means that the final file dimensions will be 8.5” x 11” exactly, and that their design will have to include some sort of white space around all four edges of the design to make sure that the file accommodates the machine’s margin printing limitations.

2) Instruct the designer to build the file with bleeds. In this case, the final file they send will be oversize (8.75” x 11.25”), which means it is no longer printable on standard letter paper. If this is the workflow you choose, you will need to print the file centered on tabloid (11” x17”) paper and trim off the extra ink once the file has printed.