I’m often sent logos and photos to create artwork with and upon receipt, I’ll respond with the phrase…“I need these in high resolution.”
You may have an inkling of what “high-resolution” means but do you really know what it is and why it’s required to produce good design communication?
To make sense of what Image Resolution is and how it affects your marketing materials it’s best to start from the very beginning with the process of creating an actual image because that’s what resolution effects: image quality.
Today, we create images with the use of cameras and digital applications but we used to create images in a traditional manner with pens, pencils and paints. That traditional process is where the theory of resolution begins.
Images & Resolution…
Grab a “ballpoint pen” and look at the tip. You’ll see the point is the shape of a ball because it was designed to create a circular-shape at the very least. Tap that pen onto an A4 sheet of paper and you’ll make a dot.
If you drag that ballpoint across the page then you’re making a series of joined dots which results in a solid line.
Covering the page with lots of dots, filling it up so it was no longer a white page would use millions of dots to produce a solid block of colour. You could do the same by drawing thousands of lines to cover the page with ink instead of using single dots.
To make things easier you could switch out the ballpoint pen for a marker where the tip is thicker and may have a different shaped head. The bigger size and shape of the marker head will make it easier to cover a page with ink because each dot/stroke covers a larger surface area. None the less, the end result will still be the same: a page covered in ink to create a solid fill.
If you create a detailed image with the thick marker then the broad point would be too big to create smaller specific detail so the smaller ballpoint pen would be the better choice to create a detailed image.
The principle that we learn from drawing and ink is that:
- All images are composed from tiny dots or shapes
- These dots can form lines and solids to build a picture
- If you drew a picture just by tapping the ballpoint pen then you could count how many dots it took to create that picture
- The size of dots can vary and have an effect on the level of detail when producing an image.
These ideas can be transferred over to digital devices, monitors and drawing apps to understand how image resolution works but use pixels and screens instead of ink dots and paper.
What is A Pixel?
A pixel is a digital unit of measurement based on a single square. Think of it as one single dot as made with the ballpoint pen.
Your devices use millions of pixels to produce an image on your screen with the use of a pixel grid. The pixel and grid are so small that you won’t notice the square appearance (like an ink line made from a series of dots). You’ll only see the zoomed out smooth lines.
Your screen will have a maximum set of pixels it can use to produce your screen image which is known as screen resolution.
What is Screen Resolution?
A common screen resolution of 1920 x 1080px results is a screen that uses a grid of 1920 pixels across and 1080 pixels down to form your screens image output. If you multiply 1920×1080 you get 2,073,600 pixels which is your actual screen resolution.
In theory, the higher the resolution of a screen, the better image quality it will display as it uses more pixels to create more detail in an image. It’s similar to using a fine pen instead of a fat marker to draw a picture.
That’s technically correct yet also untrue because screen size also has an important part to play.
How does screen size affect image resolution?
A screens size is determined by its physical dimensions:
One computer may have a 23inch computer monitor.
A second computer may have a 15inch monitor.
This only means that one screen is bigger than the other, maybe making it easier to see because it’s larger but that doesn’t mean that the bigger screen provides a better quality image. Screen resolution determines which monitor has better picture quality in combination with the screen size. Ultimately, the question is….”How many pixels can a screen use to display an image within its given space?”
How does resolution and screen size determine picture quality?
Both 23inch and 15inch screens may have a resolution of 1920x1080px but because the 23inch screen is bigger, it will either use a bigger size pixel to display the image or may have a lower pixel density to display the image. Using a bigger size pixel is like using a felt tip instead of a fine liner to draw an image on paper and that’s also similar to how pixel density works.
What is pixel density?
Pixel density is a measurement of how many pixels you can fit into a given space, and it’s how we translate pixels back into the real world when we print images.
For example, an image of 1920×1080 pixels in size will fill up a 1920x1080px resolution screen from edge to edge but how that image will translate onto a piece of paper when printed is down to the pixel density of the image and image size.
If an image has a pixel density of 72ppi (pixels per inch) then the image uses 72 pixels in every square inch of the image.
An image size of 1920x1080px at 72ppi is considered as low resolution or an ideal resolution to create an image and display it on your 1920x1080px size screen, edge to edge at face value.
On-screen , a 72ppi image might look like a massive, high-quality fullscreen image but when you print it onto an A4 sheet of paper without resizing it, it will take up less than a third of the space, maybe even a quarter of it. This is a problem when you’re working on a full-sized A4 brochure that needs to be printed.
To fit this image onto a whole A4 sheet of paper I can resize the image to fit.
On a screen and on paper, the 72ppi image of the lioness was sharp at its original size but once enlarged it gets blurry because we’re trying to stretch the image to four times its original size (288ppi). It’s like stretching a rubber band.
An unstretched rubberband will look solid and smooth in shape and texture. When you stretch it, it begins to fray and loses shape because you’re trying to stretch its molecules to double its size.
To solve we either need a bigger rubberband to fit or we need one with more elasticity. That same analogy applies to solve image resolution issues.
To get an image to fill an A4 sheet of paper, the original image needs to either:
a. Have a high pixel density of 300ppi so it can stretch and fill an A4 sheet of paper without blurring or fraying like a rubber band.
b. Or we need an image already made with larger dimensions preferably A4 size (2480x3508px) with at least 72 dpi to fit the page size exactly.
The resolution, pixel density and dimensions of an image interact with each other to play a combined part in determining the quality of an image, its size and how it can be used online and off.
Can you change Pixel Density and resolution of an image?
Yes and no.
Each piece of media whether it be a document, video or an image may have a different end purpose.
You may take a hi-resolution photo on your camera and intend it to be:
- Displayed online on your blog
- Printed as a small photo
- Printed as a large canvas banner
- Displayed on your TV as a slideshow
Each end purpose requires the photo to be produced or amended at a different resolution for optimum use. For example….
Resolution for online screen content
Although we have phones and computers all with hi-resolution screens we are still held back by internet speed. A big hi-resolution photo uploaded to the internet would take a long time to load depending on the location its uploaded to, your internet speed and your computer power.
To make all images quickly and easily accessible on a website to anyone regardless of their internet speed and computer power we “optimise” images for web so the image stays at a high visual quality but reduces its file data size and pixel density to the naked eye thus making it quicker to load.
This means that:
- We take a hi-resolution photo of 2480x3508px
- We reduce its physical size to fit into the space of a computer screen/webpage (eg. reduce to 1920x700px)
- We reduce the pixel density of the photo so it uses less pixels and data but still remains at a high visual quality. eg. change it to a resolution of 72ppi
This process optimises the image and reduces the resolution without compromising visual onscreen quality.
The only tell-tale sign that the image quality has been reduced is if a user zooms into a photo on a website and sees how the picture quality deteriorates the more you zoom in, but users don’t actually do that. Online and when navigating websites users tend to be happy with “what you see is what you get.” There’s no need to zoom in or out of images. Text? Maybe? But not images within a web design.
For web use the optimal image resolution is a low resolution of 72ppi. If you want to print that image out on a large canvas or even an A4 sheet, the web optimised image at 72ppi image won’t suffice because there isn’t enough pixels for the image to fit the A4 sheet of paper or to upscale it sufficiently without losing image quality.
To solve the problem of transferring a web based image to print is to have a high-resolution photo to begin with, one with at least 300ppi so it can be printed on an A4 sheet of paper or downsampled to use online.
Why I ask for high resolution files.
As illustrated in the previous images above, the size and resolution of a printed image and on-screen image differ immensely. What’s big on a screen could be tiny on paper and vice versa. To summarise it’s like working in-between a two-dimensional digital world and a three-dimensional real world where size is not exactly the same within each dimension. That’s why I always ask clients “how will this document be used? (web or print?)” prior to starting work. I need this information so I know whether the A4 sized document that the client requested will be a:
– A4 printed flyer (210mm x 297mm) @ 300ppi resulting in a 10mb file
– Or an A4 digital document (2480px x 3508px) @72ppi resulting in a 2mb file.
– Or an A4 looking document on screen (900px x 1200px) @72dpi resulting in a 500kb file
Once I know, my first step to producing the document using professional design tools will be to set up a digital canvas by inputting the dimensions, resolution and orientation of the canvas inline with the end documents purpose. This step is a clear and defined statement as to what we’re designing and for what end purpose. It’s like setting up the goalposts for the game and if you change the goalposts midway through then you’ve changed the game.
Once the resolution is set and the image/document is made, I can decrease the pixel density by downsampling/downscaling/optimising it (terms used to describe the process of decreasing pixel density and resolution). That’s doable because you’re reducing the number of pixels that already exist in the image without noticeably losing the image quality. Increasing pixel density (upscaling or upsampling) is another ballgame altogether. It’s doable within reason because you’re trying to conjure up pixels out of an already set value of pixels. It’s like trying to squeeze into an old pair of jeans. You might be able to do it but there might also be a lot hanging out.
To answer the question, can we change pixel density? The answer is yes. Lowering pixel density is fine to do with skill and care, and yes, we can increase pixel density within reason. In any case, to do so, we need high-resolution artwork to begin with so we have greater flexibility with what we can produce with that artwork. That’s why I always ask for high-resolution files from clients when producing art and design work. It allows me to deliver the best quality piece of work possible for you, the client.
How you’re marketing materials are affected by resolution?
Let’s be honest. The use of a low-quality image is not the end of the world. No one will die as a result of it but it does have a knock-on effect, especially as a business owner who wants to promote their brand.
Using a low-resolution file means that:
1. Your end documents may not look like what you expected.
You can see a small low-resolution image online and think “that looks like a great picture to use and print”. When you transfer that to print or stretch it to make it bigger, the pixelation of the low-quality image will show through. The small low-quality image may be a good size for a 400×400 pixel banner but on paper that’s an image size of 2.5cm x 2.5 cm. Resize it bigger and it will look terrible.
Low resolution images are misleading to those who don’t know about resolution and will create inconsistency for your brand imagery.
2. You’ve wasted time and money on your marketing.
You may have put a lot of effort or spent a lot of money into marketing elements such as a logo design or taking photographs. If they’re all low-resolution then you can only use them online at best. Reproducing them for print or bigger spaces will lead to poor results so any money spent on low-resolution imagery can be deemed as worthless beyond a single goal.
3. There’s less creativity in low-resolution files.
You’re spending time and money on a designer to design something for you but giving them low-resolution files to work with means that you’re subtracting the creative possibilities of that project. Low-resolution assets result in limited creativity. A final file may only be able to be so big. For example, you may not be able to create full screen width banner image or even a full-width document header with low-resolution imagery because theres not enough pixels in the image to fit that space. You can only edit low-resolution photos so much because their user ability is poor, and the end result will be a reflection of that.
4. You might not be able to print it
Most print houses won’t accept a low-resolution file for print reproduction. They’ll either reject your file, charge you to redesign something new altogether or will just print it and refer you to their print guidelines when you’re unhappy with the job done. Their guidelines will always state, “Use imagery with a minimum of 300dpi (dots per inch)”.
5. Ultimately, you’re not going to have the files you need to compete.
Let’s say that you and a competitor are both selling at an event. They have all their artwork in high-resolution format meaning that their designer can produce anything with top-quality reproduction. From giant banners and pretty brochures to stylish pens and funky lanyards, they can put their logo and brand imagery on anything because their design elements are high resolution, and their print work will look sharp and vibrant. You, on the other hand, have all low-resolution design elements. You can’t get anything printed sharply, if at all. Visually, you’ve created the perspective that you’re second best and it’s likely that your attendance will be overlooked and you’ll lose work.
6. Image Counts
As a business, brand, seller or retailer, your image will always be judged by prospective clients and other businesses. Your brand image is enough to make a potential buyer interested or disinterested in you. You can win or lose a sale based on the quality of your design communication.
How to get Hi-resolution files to use.
Image files are created in one of two ways. Think of it as the DNA which makes up their composition. There are raster images and vector image file types.
Raster images are common file types such as gifs, pngs, and jpgs. They’re image files composed from raster design software such as Adobe Photoshop or MS Paint or a camera and use pixels, a pixel grid and a set resolution to create imagery. They’re ideal for reproducing photos or art prints.
The problem with raster files are that their resolution and size is created set and stored at the point of inception of the image either by the software, hardware, file format or users initial requirements. After the image is created, you need to edit, upscale or downscale the image to suit your purpose.
Downscaling the image is doable but upscaling can lead to bad results so the best way to get high resolution raster files is make the initial resolution of the image at least 300ppi so it can be expendable and accommodate any use whether it be for large canvases or small web banners.
All professional photos are taken in high resolution format and then resized into several lower resolution forms to sell onwards.
Buying the cheapest and smallest version of an optimsied image will be great for web use but not for print. When buying a stock photo and if you intend on printing it professionally then make sure you buy the high-resolution version. Likewise if you want to use it for a widescreen web banner, you’ll need the high-resolution version of the photo which should have larger dimensions. For a designer, the bigger the image file the better so it can be used in any given situation.
When using a raster pixel grid every line, shape or dot needs to be placed within a regimented x and y-axis. Vector images are created using vector software, software which defies convention and the pixel grid. Instead of using the grid coordinates, it uses mathematical equations to create lines, shapes and dots anywhere on the screen. In doing so it’s not restricted by the pixels or the pixel grid and can change any line or shape to any size using calculations instead of coordinates because there is no grid. This means there is no resolution (or it has an infinite resolution).
Vector images are best used for graphics with lots of lines and shapes as opposed to photos. They’re good for designs which need to be resized to any size like a logo. They’re also great in creating precise artwork like lined illustrations or simulating hand drawn illustration and in latter years it’s even become a great tool for 3D objects and photo realistic illustrations.
Vector images can only be manipulated/viewed in vector software so to make it viewable to anyone else it needs to be converted into a raster file format for general use but that original vector image file can be resized to any size at any given time to accommodate any resolution without any distortion or demise of quality when reproduced.
In the last ten years, I’ve come into contact with an abundance of companies who couldn’t compete and secure the contracts they wanted not because of their business model, turnover or expertise but because of a lack of brand strategy and premium imagery.
Branding, imagery and design have come along leaps and bounds and everyone is at least a little image-focused today. Bigger companies want to work with proven businesses but won’t consider you unless you look the part as well. Why? Because design sells!
Content is still King but imagery is the Queen. And image resolution makes up her presentation, her intelligence and gives the King his substance. And you need both the King & Queen to compete.
As a designer I want your work to look good and to do so that I need high-resolution graphics because my, yours and your customer’s eyes will be judging you by it. I want your work to be perfect because that’s my job.
Make your brand stand out by always using high resolution imagery, especially if you want your brand to be taken seriously as a contender.