How to prepare large files for print

Some of our client work requires us to create graphics for large spaces, window graphics, whole interior spaces, billboards and trade show exhibits to name a few. Here are some things to take into consideration when preparing a file for large-format printing.

Following print requirements

It is extremely important to follow the print vendor’s requirements on size, file format and resolution. Usually, on traditional small print jobs—brochures, magazines, and fliers—the resolution for photos (raster images, which are composed of pixels or tiny dots) should be 300dpi (dots per inch) at 100% scale to ensure a sharp high quality print. When working with images that are going to be viewed from a distance and at a large size, you know you are going to have to enlarge your image which will decrease the resolution. Most large format printers require a minimum of 100 to 150 dpi at 100% final size. This also keeps the file size smaller. If you increase the size of your photo and go below 100 dpi, your photos will begin to look pixelated and blurry.

Print production check

As with all files, I always go through a print production checklist, which can be seen in one of my previous posts.

One of the first things I do is check that the document is set up to the correct size. I then check the size and resolution of any photos. Ideally, you want to start your project with images that are already at a high resolution so if you need to scale them up, you are not losing too much quality. If that is not the case and you need to increase the photo size (which decreases the resolution), make a note of the width of the image placed in the layout in InDesign. I then open the original photo in Photoshop and rescale the image to the resolution the printer requires. To do this, you need to go to “Image” in the main menu, go to the dropdown and click on “Image Size.” This will open a dialog box. Uncheck the resample box and then change the resolution to the printer’s specification. 

Then click back on the resample button, take the width size from the layout file and apply it, view it at 100% and see what it will look like at the final size. You might need to play around with some of the detail settings in the dropdown menu by the resample button to “preserve details” settings and preview which one works best. Once you choose a setting, you might need to do some manual retouching (open the image into a raw camera filter and adjust some basic controls such as contrast, shadows, clarity and texture) or add or reduce noise to make your image look its best.

You can also go to the Photoshop Filter “Neural Filters,” click on the .jpg artifacts and change the strength to high, medium or low and see how this affects your image. This will fix the flaws that were a result of too much image compression that created blocks of pixelation. It blurs and smooths the edges so you get a more even tone for the photo.

Remember, you will view your artwork at a large size, and when you enlarge a photo, you also need to make sure you remove any unwanted objects or logos on shirts or hats in your photo that will distract from your design. 

Print before finalizing

To get a sense of how the final product will look, I usually print out the small version of the artwork on 11×17 paper, and then I print out several slivers at the actual size and hang it up on our office walls, standing at a distance equivalent to what you would be viewing the final full-size display, making sure nothing is blurry or pixelated. It is equally important to look at your text at the final size and check the kerning (space between letters) and the leading to confirm everything is legible and readable. Also, be mindful of your margins. Make sure you set them at least 1.5 to 2 inches away from the trim, ensuring that nothing looks like it is being packed into your space. Creating this nice white space will make your design look better.

For every project I work on, it is so rewarding to get to see the finished product. To see for yourself, here is a link to a pet client and the trade show exhibit we created for them recently. This entailed a lot of Photoshop work, outlining furry dog photos and making sure the image quality looked great at the final size. Working on jobs that include cute cuddly dogs makes my job more fun!