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Advanced Image Set-Up

This article describes advanced topics regarding images used for Print on Demand

Samuel Gichuhi avatar
Written by Samuel Gichuhi
Updated over 5 months ago

Table of Contents

Image Resolution vs Print Size

Determining Image Resolution for specific Print Sizes

If you haven’t taken photos or scans of your work yet, and are wondering what resolution you need for these images, you can use this table to determine what size images would be required to support the largest print size you wish to offer.

If you already have photos or scans and know what resolution these are, you can use this table to determine what sizes you may be able to offer based on their resolution.

Desired Maximum Print Size (inches)

Best Resolution (300PPI)

Acceptable Resolution (150PPI)

8x10

2400x3000px

1200x1500px

10x12

3000x3600px

1500x1800px

16x20

4800x6000px

2400x3000px

20x30

6000x9000px

3000x4500px

30x40

9000x12000px

4500x6000px

Note: And although prints at this size can be purchased, there is no guarantee that these will necessarily meet your expectations. If you have any doubts you should order a test print. You can do this as a self made order, and this will allow you to verify for yourself how any image will print at your desired size, although the results may vary depending on the style of the artwork, the quality of the image, and the medium being used.

Note: And although prints at this size can be purchased, there is no guarantee that these will necessarily meet your expectations. If you have any doubts you should order a test print. You can do this as a self made order, and this will allow you to verify for yourself how any image will print at your desired size, although the results may vary depending on the style of the artwork, the quality of the image, and the medium being used. To learn more about creating a self-made order, you can refer to this article: https://artstorefrontssupport.zendesk.com/hc/en-us/articles/360028831931-Everything-You-Need-To-Know-About-Retail-Self-Made-and-Wholesale-Orders

You can also create cropped test prints, which is a more economical option if you’re looking at prints at large sizes. For more information about how to set these up, please refer to this article: Cropping Print Product Images to Preview Large Sized Prints Cheaply

For small print sizes (under 10x12in) that are 72PPI, these may not give you the best prints, especially when viewed up close where they may lack detail. However for very large print sizes where the optimal viewing distance is further away, this relative lack of detail is no longer noticeable unless the image is viewed from up close. For prints above 10x12in 150DPI will usually be fine, and for prints above 16x20 even 72DPI can look acceptable (although the style of the artwork or photograph can affect this).

To manually determine the maximum print sizes at different DPI values for an image, this can be calculated from the resolution of the image as follows.

For 300DPI: print size = (width / 300) x (height / 300)

For a 3000x4000px image, this is (3000/300) x (4000/300), or 10x13.3”

For 150DPI: print size = (width / 150) x (height / 150)

For a 3000x4000px image, this is (3000/150) x (4000/150) or 20x26.6”

Note: Increasing the resolution of your images by upscaling them in Photoshop or other general-purpose image editors is not recommended, as if done incorrectly this will create images that may not print well at large sizes.

Determining Largest Print Size from Image Resolution

If you’re starting with photographs of your art, you can determine roughly how large you can print your images using this chart. Just find the resolution of your image, then compare it with the height and width on the chart to get a rough estimate of the print size at 300DPI.

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Note: It is possible to print the same image much larger, as the auto-generated size list that is created and assigned to an image once it has been uploaded into your Art Print Store supports print sizes which go down to 72DPI, which is a much lower level of print detail. However 300DPI is considered the “optimal” level of detail, and prints which are at this setting (or higher) will be reproduced most accurately when printed.

If the size shown isn’t large enough but you still wish to offer larger prints, there are three ways to work around this:

  • Re-photograph the piece, if you can take larger images. Higher resolution images will allow larger prints to be created from them.

  • Allow prints to be created at lower DPI values. In most cases images can be printed with good quality at lower values. 225DPI will usually produce excellent images results, and in some cases even prints at 150DPI will print quite well. (However you may wish to order test prints to check the output before listing them on your site)

  • Use speciality software such as Topaz Labs Gigapixel AI to create large images from your smaller source images. This can often create images that are 2x the resolution and look much cleaner and well defined once processed. However it doesn’t work with all images, being reliant upon the quality of the original image and also affected by the style of the artwork.

Standard Print Sizes

Due to the way print sizes are handled for images uploaded to Art Print Stores, it’s not possible to have a single image uploaded which is available in what are referred to as “Standard Print Sizes”. This usually refers to the range of sizes in which empty frames are available from retail or specialty stores, with the intent of purchasing a print from your site and then buying a standard-sized frame and framing the print themselves.

However your site doesn’t support multiple aspect ratios for an image; instead it’s designed around being offered in multiple sizes which all share the same aspect ratio. For example if you have an image which has the aspect ratio of 4:5, the only standard frame sizes that would match this would be 4x5”, 8x10”, and 16x20”.

Frame Size

Aspect Ratio

4x5”

4:5

5x7”

5:7

8x10”

4:5

11x14”

11:14

16x20”

4:5

20x24”

5:6

24x36”

2:3

30x40”

3:4

The Art Storefronts platform is designed around being able to upload your images and have custom framing offered to fit your art, rather than having to crop your image to match specific frame sizes.

Cropping and Aspect Ratio

The reason is that images may sometimes be cropped to match the print size selected for an order. When images are uploaded to the Art Print Store, the system will automatically generate a range of print sizes starting from the smallest supported and going up to the largest size supported (either 99x99, or whatever can be printed at 72DPI).

The size algorithm has been set up to round sizes down to the nearest whole inch, so for example if the size would be 10x16.4", it will be set at 10x16" (or for sizes which would be half an inch or over, 10x16.6", it would be 10x17"). This rounding of sizes to whole inches was requested by print studios initially, and then when the system transitioned to having dedicated vendor partners such as Bay Photo and Graphik Dimensions this has been continued, and it’s not possible to disable this or to opt out of it.

There are a couple of things you can do to adjust your images so prints will either not be cropped or will only be cropped in minimally noticeable ways.

The first is to have your images sized so they will match a whole aspect ratio as closely as possible. For example an image which is 4000x3000px in size, this will have an aspect ratio of 4:3. This will allow you to set up your print sizes in matching ratios (for example at 4:3, sizes would be 4x3, 8x6, 9x12, and so on, increasing in increments of 4x3), and this would be printed without any need for the source image to be cropped to match the print size.

However if your images are sizes which don't match, it may be necessary to change the image, either by cropping or for images with a solid colour background by expanding the size of the canvas to a whole ratio. (By whole ratio I mean an aspect ratio with two whole numbers: 6.6:4 wouldn't work, for example. However something like 6.5:4 could be refactored as 13:8, and this would be usable although the size range would be limited to 13x8, 26x16, 39x24, etc)

For an image with a ratio that's not quite correct, you can adjust the height or width to match. For example with an image that's 6600x4000 (ratio of 6.6:4) you could take any of these solutions:

  • crop it down to 6500x4000 (a ratio of 6.5:4 or 13:8).

  • expand the canvas to 6600x4400 (a ratio of 3:2)

  • crop the image to 6000x4000 (a ratio of 3:2)

One other consideration is that certain media or style finishes may benefit from having up to ¼" of bleed on each side at the smallest print size you've enabled for a product. Metal prints and matted or framed and matted prints will often have issues if the source image has detail within that area, as in the printing process details may be obscured if they are within ¼" of any edge of the image. To determine what this means in relation to your source images, you can take the resolution of each image and divide the height or width by the corresponding print height or width, and then divide that by 4.

e.g. 6000x4000 with a smallest print size of 9x6".

6000 / 9 = 667

667 / 4 = 167

This means that for that image, anything within that distance of the edge of the image (167pixels) may be affected if it's printed as a metal print or as a matted or framed and matted print.

If you have images which have substantial detail which extends right up to the edge of the image or within the ¼” border, you may wish to investigate adding a solid colour border around the image. Alternatively if the detail is a small area, such as a signature, it may be possible to use Photoshop to change the location of this and then fill in the area from which it has been removed in such a way that it’s unnoticeable.

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