The ABCs of PDF, JPEG, PNG, AI, PSD, and INDD Files

Learning the difference between PDF, JPEG, PNG, AI, PSD, and INDD can feel like you're learning your ABCs all over again.


I'm here to help you. Below, I've defined these design files and listed some examples of how to use them.

PDF - Portable Document Format


You have probably encountered this file before. It is a standard file that most computers can open with applications like Preview and Adobe. It retains images, typefaces, and formating. It's perfect for sending a signed contract, a resume, or a brochure over email.

JPEG - Joint Photographic Experts Group


When you take a picture on your phone and post it on social media, it's most likely in a JPEG file. Like PDFs, most computers can open JPEG files. These files are the most common image file. You can use JPEGs for photos and digital illustrations.

PNG - Portable Networks Graphic


PNG is my favorite file type :) It's a low-resolution file type that allows for a transparent background while preserving a high-quality image. You can open these files on most computers. I use these PNG files for logos and other design elements on my website.

AI - Adobe Illustrator


Unlike PDF, JPEG, and PNG files, you can only open AI files if you have the program Adobe Illustrator installed on your computer. This program allows me to compose illustrations in Raster (using pixels) or Vector (using formulas).


Raster images have a fixed resolution. In other words, they are made up of pixels. You can only print them to a specific size before they start looking pixelated. Vector images, on the other hand, are made up of math formulas. So you can print these images at any size without getting pixelation. With Adobe Illustrator, I can convert a raster image to a vector image.


AI files also help me preserve design elements separately so I can edit them on the fly. AI files are my favorite type of file to use when working with clients and third-party printers. I can use AI to export my designs as other file types like PDF, JPEG, and PNG.


PSD - Photoshop Document


Yes guessed it! PSD are files created in Adobe Photoshop. You must have that program installed on your computer to open the file. Using Photoshop, you can only create and edit Raster or pixel-based images. But, you can save these images as other file types like PDF, JPEG, and PNG. PSD files also make it easy for me to work with clients and third-party printers.


INDD - InDesign Document


This last file type, INDD, is my favorite file type to use when setting up a digital or printed publication, like a catalog or a picture book. It helps me set up multiple pages with ease. And it converts my work into PDF, JPEG, PNG, AI, and PSD files. I'm currently using an INDD file to email PDFs of my latest picture to literary agents. And one day, I'll email the same INDD file to a third-party printer to publish my book.

Resources

Qualls, Rosee "The 10 Essential Graphic Design File Types and When to Use them." Planoly. May 20, 2020

".JPG, .EPS, .PSD, Oh My!: Common Design File Types Explained." The Papermill Store. November 17, 2014