The following is a set of instructions for correctly sizing digital image files of artworks for reproduction in print. 

In Adobe Photoshop:

Begin with the largest image (highest resolution, or largest file in megabytes) that you have gotten from your professional photographer, or which you have taken yourself in the studio. The highest quality photoshop files made by a professional copy photographer are typically saved and delivered to the artist as uncompressed RGB .tiff files, but jpeg files work too, as long as the resolution is high and with only minimal compression applied. 

1: Open the file in photoshop, go to the "image" menu in the header bar, scroll down to "image size" and when that sizing menu opens, set the size in inches to correspond with whatever size limitation you have been given by the printer or designer of your publication (i.e. for invitations, websites, books, etc.). Maximum allowable size for print will always be the widest or tallest dimension given – so, for an 8"x10" size constraint, use 10" as your biggest dimension and the proportionally correct corresponding dimension will automatically be set in the sizing window.

2: While the image sizing window is still open, look at the bottom at the "Resolution" field, which is automatically set at "Pixels/Inch" in all US systems (it can be changed to CM in that field as well). Now set your resolution at 400 Pixels/Inch. If it starts smaller than that number, be aware that you are beginning with a low-res file and that the sizing tool will only be adding empty pixels to the resolution – and not making it clearer. You always want to start with a high-res file!

3: save your newly re-sized image with a new title, so as not to overwrite your original file and save it to your desktop or to a folder where it can easily be found.

For images sent from iPhone cameras:

iPhone cameras capture images in a very large dimension in inches, but always at only 72 ppi resolution. If you simply attach an iPhone photo to a text or email and send it to the designer (me in this case) at its original capture size, it will generally be large enough for me to work with for print. Just be sure not to select a small or low-res attachment size. You always want to send it at full resolution from your photo library. 

My phone number for texting images is (505) 603-5360

Email is thefisherpress@gmail.com (always be sure to check that your outgoing mail server is attaching the image at full size!!)