Resolution for photos, wall art and posters?
(See below for Aspect Ratios of each print and poster.)
Higher resolution photos are clearer and contain more detail.
Digital image resolution is expressed as pixels (or dots) across by pixels down, such as 640 x 480, meaning 640 pixels across by 480 pixels down. The best printable resolution is 300 dots per inch.
Extremely low resolution will look “blocky” or pixelated. Imagine only 4 dots per inch: you would see four colored squares instead of a picture. When there are many pixels, your mind blends the tiny blocks together to form an image.
The digital camera is the most important factor in determining quality of digital images. The greater the number of pixels (up to 300 per inch), the higher the quality of the digital image. Some low-cost cameras give a set number of pixels and shoot only one resolution. Higher-priced cameras offer a pixel range, which enables you to select the best resolution for the size image you want.
Not all photos require high pixels per inch. For instance, you are likely to stand back from a poster, and your eye will blend the pixels together, so 90 pixels per inch is the minimum recommended resolution for posters. The subject matter can also be important: for instance, if you are printing a picture of a crowd of faces or a group shot, and you want to recognize faces in the crowd, you will need a higher pixel count to ensure that each tiny face has a enough visual information.
Use the following chart as a guide for determining the best resolution for various print sizes. Note that the 4xD (Digital) size is the same ratio as most digital cameras — 1.333 (1200 x 1600 dots) — so no cropping is required when printing these photos. The 18×24 and 30×40 also have the same 1.33 ratio and require no cropping for most digital cameras.
Add an eighth of an inch to each side for a perfect print
When creating a print product like a 4×8 card or poster, add 1/8 of an inch to each side. For 300 dots per inch, that’s 37.5 pixels or 75 pixels for both sides. A perfect 4×8 card would be ((4×300)+75) X ((8×300)+75) or 1275 by 2475. The 37.5 pixel border is not printed, so no important photo elements (faces, type, etc.) should be in that space. Note that the 1/8 inch pixel border decreases as resolution decreases: at 200 dpi, 1/8 inch is 200/8 or 25 pixels. This also changes the aspect ratio.
| Size | Borderline: 150 res |
Better: 180 res |
Good: 200 res |
Best: 300 res |
Aspect Ratio (L/S) |
| Wallets (2″x3″) | 300 x 450 | 360 x 540 | 640 x 480 | 600 x 900 | 1.50 |
| 4 x D (4 x 5.33) | 600 x 800 | 720 x 960 | 800 x 1066 | 1200 x 1600 | 1.33 |
| 4 x 6 | 600 x 900 | 720 x 1000 | 800 x 1200 | 1200 x 1800 | 1.50 |
| 4 x 8 Card | 638 x 1238 | 765 x 1485 | 850 x 1650 | 1275 x 2475 | 1.94 |
| 5 x 7 | 750 x 1050 | 900 x 1260 | 1000 x 1400 | 1500 x 2100 | 1.40 |
| 8 x 10 | 1200 x 1500 | 1200 x 1500 | 1600 x 2000 | 2400 x 3000 | 1.25 |
| Posters | Borderline: 90 res |
Better: 150 res |
Good: 180 res |
Best: 300 res* |
Aspect
Ratio (L/S) |
| 11 x 14 | 990 x 1260 | 1650 x 2100 | 1980 x 2520 | 3300 x 4200 | 1.27 |
| 12 x 18 | 1080 x 1620 | 1800 x 2700 | 2160 x 3240 | 3600 x 5400 | 1.50 |
| 16 x 20 | 1440 x 1800 | 2400 x 3000 | 2880 x 3600 | 4800 x 6000* | 1.25 |
| 16 x 24 | 1440 x 2160 | 2400 x 3600 | 2880 x 4320 | 4000 x 6000* | 1.50 |
| 18 x 24 | 1620 x 2160 | 2700 x 3600 | 3240 x 4320 | 4500 x 6000* | 1.33 |
| 20 x 20 | 1800 x 1800 | 3000 x 3000 | 3600 x 3600 | 6000 x 6000* | 1.00 |
| 20 x 24 | 1800 x 2160 | 3000 x 3600 | 3600 x 4320 | 5000 x 6000* | 1.20 |
| 20 x 30 | 1800 x 2700 | 3000 x 4500 | 3200 x 4800* | 4000 x 6000* | 1.50 |
| 24 x 36 | 2160 x 3240 | 3200 x 4800* | 3200 x 4800* | 4000 x 6000* | 1.50 |
| 30 x 40 | 2700 x 3600 | 3600 x 4800* | 3600 x 4800* | 4500 x 6000* | 1.33 |
* The longest side of any uploaded image is a maximum of 6000 dots. When the longest side is 6000, the other side is calculated to have the same number of pixels per inch.
What is the best resolution for a large poster or framed print?
The largest image that iq Media Prints uploads is 36 megapixels or 6000 x 6000 dots, so, if possible, you want the longest side to be 6000 dots and the shorter side to be proportional. For instance, if you want a print that is 42″ x 30″, the best possible image would be 6000 x 4286. The image must also be 30MB or less; if the original is more than 30MB, try saving as a JPG or adjusting the JPG compressions.
How can I see the size of my images?
The are many different photo/image applications being use and each one take a little bit different approach to find out the image information
For Adobe Photoshop: To find image information in Photoshop, you can use the Info panel or the File Info menu:
Info panel
Displays information about the image, including document size, profile, dimensions, and current tool. You can access the Info panel by clicking the Info panel tab or selecting Window > Info. You can change the information displayed in the Info panel by clicking the triangle in the upper right corner of the panel and selecting Panel Options.
File Info menu
Displays metadata about the image, including Description, IPTC, and Camera Data (EXIF). You can access the File Info menu by selecting File > File Info with an image open. You can edit metadata by modifying the desired fields and saving your changes.
You can also check the size and resolution of an image by going to Image > Image Size
For Corel Paintshop Pro: Open an image file, from the top menu click [Image] Scholl down and click on [Image Information]
For CorelDraw: simply right click on an image and click on [Properties] here you will be presented with all the information about the image