Layman’s Guide to Resolution

Layman's Guide to Resolution

Image requirements might be a boring stuff but very significant into achieving high-quality photos. Here's our layman's guide to resolution, sizing and formats... yawn ­ I mean yay!

So you’ve got a theme for your room and have found your perfect image. You’re super pumped about it, only to find that there’s a whole load of boring techy hoops like this layman's guide to resolution to jump through before you can send your image off to print. What a dampener.

Pixels and Vectors

What is a Pixel?

A pixel (‘picture element’) is a tiny unit of illuminated colour on a screen, which is used (in the thousands!) to compose an image. When you take a photo with a digital camera,in encodes the image into pixels so it can be viewed on a screen!

What is a Megapixel?

1 million pixels = 1 megapixel. So if you have a photo that is 1720 pixels in height by 1280 pixels wide, you can multiply those numbers together to find how many Megapixels the image is in total (so in this case, it would be 2,201,600 pixels ­ or 2.2MP!)

This is really a measurement of what the image dimensions are and how big it is.

What is a Megabyte?

A ‘byte’ is a measurement of memory on your computer (1 million bytes = 1 megabyte). You can think of it as a ‘weight’, or how heavy your file is on your computer. So a 2.2megaPIXEL image might ‘weigh’ less than 1 megaBYTE, or it might weigh more than 5megaBYTES! It depends on what file type you’re using, and the file compression settings (we’ll get onto those in a minute!)

Canvas Megapixel Requirements:

Because a pixel is a size unit, if you try to enlarge an image with a certain amount of pixels, the image will ‘pixelate’ and look fuzzy. For this reason, we have some minimum image requirements for image megapixels for each of our canvas sizes, to make sure they don’t get the fuzzy, pixelated look when printed!

A4: 1 Megapixel +

A3: 2 Megapixels +

A2: 4 Megapixels +

A1: 8 Megapixels +

A0: 16 Megapixels +

Regular Panoramic (100cm x 30cm): 6 Megapixels +

Jumbo Panoramic (150cm x 50cm): 14 Megapixels +

Baby Square (30cm x 30cm): 2 Megapixels +

Mummy Square (40cm x 40cm): 3 Megapixels +

Daddy Square (60cm x 60cm): 6 Megapixels +

What is a Vector?

A vector is actually a mathematical formula that represents both a quantity (or size) and direction. When an image is created a vector, it is not made up of pixels, but rather plotted points on an unseen grid. This means that you can scale a vector image to any size and it won’t lose quality, because the mathematical formula will simply adjust to the new size. Vector files should only be used for graphics and digital artwork, not photography.

Sizes and Resizing

How Do I Find My File Size?
To find the size of your photo, simply right-click (or Ctrl click) your image and select ‘Get info’ or ‘Properties’ (depending on if you’re using Apple or Windows). Here you’ll be able to see the dimensions in pixels:

Layman's guide to resolution: Dimension in pixels

Layman's guide to resolution: Dimension in pixels

If you’re looking through lots of images and want to filter by dimension (megapixels) or‘weight’ (megabytes), go to your image folder, select ‘View’ and order by ‘dimension’ or‘size’:

Layman's guide to resolution: Filter by dimension
Layman's guide to resolution: Filter by dimension and size

Layman's guide to resolution: Filter by dimension and size


What Does ‘dpi’ Mean?
Dpi (or ‘Dots/pixels per inch’) refers to the density of pixels in an image. It helps you understand how large a photo can be printed or displayed.

It is recommended that if you want your image to be displayed on the web, it should be saved as 72dpi. This is because screens can’t usually process more than this, so there’s no point in saving it as anything more ­ it’ll just make the file ‘heavier’ on your computer!

For print, images should be saved at 300dpi. Good printers can handle this kind of density, and it leads to a seriously crisp, high quality print! If your image size can’t quite handle 300dpi, the minimum you could go to is 150dpi if necessary.

Aspect Ratio and Cropping

Why Can’t I Make My Square Photo Rectangle?
An aspect ratio refers to the proportions of your image, and is important in making sure your image doesn’t distort when resizing. So for example, if you have a photo that is 1280 pixels wide and 720 pixels in height (a ratio of 16:9), and you want to resize it without making it look like it’s been stretched,you need to stick to the ratio of 16:9.If you resized an image with a ratio of 16:9 to a square (1:1), it would look squished and distorted. So in order to make your image fit within a square, you would need to crop it(ie, only use a square portion of the photo). Below is an example of how this works in the free online image editing tool, Picmonkey:

Layman's guide to resolution: Aspect ratio and cropping

Layman's guide to resolution: Aspect ratio and cropping

Compression and File Formats

What are the Different File Types for?
JPEG: This file format is perfect for images with more than 256 colours (ie. photographs and complex Photoshop projects). You can determine the quality of a JPEG file as a percentage; so when you save an image as a JPEG you can set whether you’d like to save it at 30% or 100% quality, for example. This is useful if you want to make the file‘weight’ (megabytes) smaller to upload online, or as high quality as possible for printing.

GIF: This file format can only process up to 256 colours, so is best used for very simple artwork with only a few colours. GIFs are highly compressed, small files that are designed to be quick to load and easy to send, so should really only be used for web purposes.

PNG: To get past the limitations of quality associated with GIF files, PNGs were created! These files are designed to load fast but still look high quality, making them perfect for online use. They also support transparency.

TIFF: Similar to JPEG files, you can choose the compression/quality of your image using percentages when you save it as a TIFF. The main difference is that you can alter the background of a TIFF to be transparent ­ useful for a photograph/graphic mix!

VECTOR: As explained above, vector files can be scaled easily without losing quality,and are best used for graphics and digital art. Because vectors are based around paths and shapes to build an image, they can’t process details such as colour fades or complex brushes very well, so for that a PNG or TIFF would be better.

What Format Do You Need for Printing?

We always ask for JPEG files for printing on canvases, because they provide the best file quality. However, if you have a vector graphic that you would like us to resize for you, you can send that to us directly!

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