All About Print: Part 3 (File Formats).

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Adobe’s Creative Cloud (CC) is a suite of creative applications that includes print design programs Photoshop, Illustrator and InDesign. CC is the industry standard design software and as such is accepted at all print suppliers. Programs such as Microsoft Word, Powerpoint and Publisher are not supported and should generally be avoided when creating graphics for print production.

Photoshop, Illustrator and InDesign are the three main programs used in the print design world, and they have a variety of file formats available to export out from their native file type. The native file type is what the ‘default’ file of the application is, or basically, what the application works with whilst creating and working on the file. This can be saved for future use, and can also be saved or exported as a different file format for publication or sharing. For Photoshop, the native file format is a PSD, for Illustrator it is an AI and for InDesign it is an INDD.

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What Each Program Is Used For

These three programs have very different duties - Photoshop is used for image editing and compositing of ‘raster’ aka ‘bitmap’ images like photos, whereas Illustrator is used for, you guessed it, illustrations and ‘vector’ graphics like logos. InDesign is a page layout application, similar to Microsoft Word but a much more comprehensive, professional design based piece of software. InDesign brings together your files from Photoshop and Illustrator and allows you to lay them out on a page, and also allows you to style the text. For example, say you were designing a brochure for a winery. You would create the layout in InDesign, but you would open the pictures of the winery in Photoshop first to do things like colour correction, remove anything unnecessary etc. You would then ‘place’ the images into the layout in InDesign. The logo for the winery would be a vector file so it could be created in Illustrator and then placed into InDesign. You would complete the layout in InDesign and save a native file along with exporting a PDF for printing.


Appropriate Image Formats In Photoshop

In the past, you would use the native PSD (Photoshop Document) format for working on files inside of Photoshop. A copy of this working file would then be saved as a TIFF for placement into a page layout program like InDesign (back in the day there was other programs called PageMaker and QuarkXPress). Nowadays, a native PSD can be placed into InDesign with no problems. However, my personal workflow is keeping a layered, RGB Photoshop file as the native ‘working’ file, and then flattening this and converting to CMYK to save as a TIFF for use in InDesign. I don’t flatten the TIFF file if transparency is being used.

SAVING FOR PRINT

When saving a TIFF, you can choose whether to flatten the layers or leave them - on the Save dialog box there is a checkbox for ‘Layers’ that I generally leave off. Once you press Save, a secondary dialog box pops up with the TIFF options on what compression and byte order you’d like. Always choose None for Image Compression, otherwise your TIFF becomes a ‘lossy’ file and will degrade in quality with each save. Byte Order should be what format the file will be used in, but most programs open files from either format. Image Pyramid can be left unchecked as not many programs support this. Save Transparency can be checked when saving a transparent file. And finally, I usually select Discard Layers and Save a Copy so that I am getting a TIFF with only 1 layer and therefore its optimum file size.

SAVING FOR SCREEN

If you’re saving the image for on-screen use and this particular file will not be printed, it is best to leave the image in RGB colour and save as a JPG. This is great for proofs of designs, and sharing/emailing photos quickly and easily. In Photoshop you simply choose File > Save for Web and you are presented with a dialog box where you can select your file type and compression options. Most of the time your file type will be JPG and you will need to work out the balance between file size and image quality, as obviously, the lower the file size, the less in quality the image will be. Sometimes, it is feasible to save a GIF, for simple graphics with low tonal ranges, like logos, that generally are ‘flat’ colour.


Appropriate Image Formats In Illustrator

Illustrator is a lot easier than Photoshop to manage files from. Basically, there are two types of files from Illustrator - the native AI format, and the EPS format, although the EPS format is quickly becoming redundant as Adobe CC becomes the norm across all creative industries.

It used to be that you would design your vector work in Illustrator and have your native AI file, and then save an EPS for exporting to supplier, for example, a sign writer, as in the past they would use Corel Draw. Now that more people are using CC, sending an AI is just as accepted.

PDFs can also be saved out of Illustrator and personally I find this works well for saving a logo, for instance, which isn’t going to be placed into a layout in InDesign (where it would be saved as a PDF).


Appropriate File Formats In Indesign

This is even more simple than Illustrator - in InDesign, you only have the INDD native file format. Once you want to get your document printed, whatever it may be, from a simple 1 page flyer, a 2 page/sided business card, or a 12 page booklet, you export the file out as a PDF, and that’s it! Inside of InDesign, by choosing File > Export you are given the option to create a PDF that is Interactive (for use on screen with buttons etc) or for Print (for print use). We usually leave the Print option as our default and only change to interactive if we are indeed, making an interactive PDF document that requires buttons and videos embedded in it for example. The rest of the time, we will use the Print PDF setting. Once you choose this and decide whereabouts the file is to be saved, press Save and you will be presented with a new dialog box for Exporting Adobe PDF. Here, we use only two of the presets: Smallest File Size (for proofing) and Press Quality (for printing). It is important to remember to check Use Document Bleed Settings under ‘Marks and Bleeds’ when creating a Press Quality file for printing - our tip would be to save yourself a preset with this checked!

We’ll cover files a bit more in the coming weeks when we discuss Image Resolution and raster versus vector images.

All About Print: Part 2 (Colour).

As the technology around printing continues to push boundaries, colour becomes more economical to print, thus allowing it to be a very permanent fixture in all visual communication from newspapers and magazines to large format wallpapers and billboards. With the advent of low-cost full colour printing and developments like six-colour hexachromatic printing, colour is affordable and it is everywhere. This is why it helps to have a basic understanding of colour, especially if you are a professional designer or even a hobbyist, as colour is one of the most important tools in graphic design. Not only are there an almost infinite number of variations available at our disposal, but there are countless ways of combining them across many different types of media.


Basic Terminology

You’ll hear a lot of different terms thrown around when talking about colour. Here, we’ll investigate some of the more useful ones. To break it right down, there are basically three different ways to describe colour: Hue, Saturation, Brightness.

Hue

Hue

Hue refers to a unique colour’s name that helps us visually distinguish between one colour and another. Basically, it is the generic name of the colour - for example, red, blue, yellow.

Saturation

Saturation

Saturation essentially means how pure or how grey a colour is. Not to be confused with how light or dark it is (see Brightness below). Saturation describes if the colour is high intensity - pure and bright, or low intensity - dull and grey.

Brightness

Brightness

A single hue (colour) will have a huge amount of variations ranging from light ‘tints’ to dark ‘shades’. The more white that is in a colour, the lighter it becomes, and it is known as a tint. On the other hand, a colour with more black in it becomes darker and known and a shade.

Hue, Saturation and Brightness can be manipulated easily using image editing software and designers can now easily change the entire appearance of an image in a matter of minutes.


The Colour Wheel

RGB

RGB

The colour wheel shows primary, secondary and tertiary colours, and a full wheel will also show tints and shades of these colours (as above). Primary colours are red, yellow and blue - this is not to be confused with colour ‘models’ used to display colour on screen or in print (more detail on this below). Secondary colours are produced by mixing any two primaries together, resulting in orange, green and violet. The six tertiary colours are made by mixing a primary colour with the secondary colour closest to it on the wheel, producing red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet.

So we now have access to 12 fairly basic colours, and once we add their tints and shades to them (as in the image above), the choices start becoming endless!


Additive And Substractive Primaries

RGB

RGB

In order to have a good understanding on how colour works, it is essential to know that coloured light and coloured pigment do not operate the same. Coloured lights, or ‘additive’ colours, are represented by the RGB system. Coloured pigments, also know as ‘subtractive’ colours, are represented by the CMYK system. Put simply, when viewing an image on a screen, which is made up of coloured lights, it may not appear the same as when it is printed, using the CMYK system.

RGB stands for Red, Green and Blue and it is an additive colour model where red, green and blue light are added together in various ways to reproduce a broad range of colours. When all three colours are added together, the result is white light. As mentioned above, the RGB colour model is used to represent images on screens such as televisions, computer monitors and displays on devices such as smart phones and tablets. Cameras and scanners capture images in RGB.

CMYK

CMYK

RGB is what is known as a ‘device-dependent’ colour model. This means that different displays will reproduce a given RGB value differently - so what RGB colour I see on my computer monitor can differ to the colour you see on your computer monitor, and again on your smartphone. It is important to remember this when designing and also when sending and viewing design proofs.

The range of colours produced by a colour model is known as it’s ‘gamut’. The RGB colour gamut can reproduce around 70 percent of the colours visible to the human eye. The CMYK colour model can’t reproduce as much as RGB so when designing be aware of this limitation. It is a common mistake of designers (both hobbyists and professionals alike) to submit artwork for printing in RGB. The results upon completion can be slightly underwhelming! RGB is able to reproduce brighter, more saturated colours simply because it is based on light. Your monitor is not a piece of paper!

RGB is used for anything that will be displayed on-screen for example; websites, apps and web advertisements.

CMYK stands for Cyan, Magenta, Yellow and Black and it is a subtractive colour model used for colour printing. Inks in the CMYK model ‘subtract’ brightness from the white or brightness of the paper, reducing the amount of light being reflected. CMYK is the opposite of RGB where white is the natural colour of the paper and mixing the coloured inks together results in black. The ‘K’ in CMYK stands for ‘Key’ - when printing, the three colours Cyan, Magenta and Yellow align with the Black, making it the ‘key’. Another way of explaining it, although not correct, is that because ‘B’ is already being used by Blue in RGB, ‘K’ is used as it is the last letter in Black.

The important thing to remember is that the CMYK colour model is also ‘device-dependent’, so colours can vary from printer to printer. As is the case with RGB, CMYK only reproduces a subset of the spectrum visible to the human eye. As mentioned in RGB above, the gamut of CMYK is less than that of RGB, making it a difficult proposition to design a printed piece, as you are viewing it on an RGB screen.

In colour printing, the four colours of CMYK mix together to create millions of colours. This process is often referred to as ‘full colour printing’ and can also be known as ‘four colour printing’.

We will cover CMYK and printing in more depth when we discuss the different printing processes in the coming weeks.

All About Print: Part 1.

All about print is a series of educational articles focused on the world of ink and paper, something we’re hugely passionate about here at Left Bank Gallery. Every fortnight, we present a new topic full of helpful information with the aim of helping our clients better understand the vast industry that is printing.

To start the series off, we’ll begin with an overview of the topics we will cover in the coming weeks.


Colour

Colour is by far the most difficult aspect of printing. Not only do different devices, like scanners and cameras, capture colours differently, but every screen/monitor will display colour differently. Monitors will display colour differently depending on the ambient light, so the type of light in the room, and the way it reflects off the walls, can influence what colour is shown. And if that’s not enough, every printer will interpret colour slightly (and sometimes significantly) different to the next.

Let’s not forget that colour is perceptual too! The lovely lime green I see may look more dull and olive like to you.

Another consideration when talking about colour in printing, is the colour ‘mode’. You may have heard the terms ‘RGB’ and ‘CMYK’ thrown around before. These are colour modes - RGB stands for Red, Green and Blue - the colours that are used to display digital images on screens including your television, your computer monitor, and your phone. RGB is not used for printing.

The RGB and CMYK colour modes. Notice how when two colours overlap, it creates a colour from the opposite mode i.e. Blue and Red in RGB overlap to make Magenta - however it is a vivid magenta, whereas the CMYK Magenta is less vibrant.

The RGB and CMYK colour modes. Notice how when two colours overlap, it creates a colour from the opposite mode i.e. Blue and Red in RGB overlap to make Magenta - however it is a vivid magenta, whereas the CMYK Magenta is less vibrant.

CMYK stands for Cyan, Magenta, Yellow and Black (K so as to not be confused with Blue, or because it is the ‘Key’ colour). CMYK is the colour mode used for most printing we see today. The four colours mix together to create millions of printed colours.

We’ll cover the nuances of colour management and colour modes in more depth when we dedicate a whole topic to it in a few weeks time.


File Types

With the proliferation of the internet and personal computers in the past decade and a bit, almost everyone has access to tools to create designs or artwork. However, most consumer program suites don’t create the correct file types necessary for high quality reproduction on a printing press.

PDF files are great for printing.

PDF files are great for printing.

The most common filetype in today’s digital world would have to be the JPEG (Jay-Peg) or JPG. This file format is used primarily for photos as it has a great knack of compressing the files size so it is easily downloaded and viewed. The fact that it is a compressed file makes it not ideal for printing.

Another common format is the PDF. This generally is the preferred format for printing in, as the PDF, when saved correctly, does not compress files like a JPG does.

TIFF files are another format great for printing, as they are a ‘lossless’ file type that allows for high quality files to be saved time and time again, without any compression. These are superior to JPGs, but they are generally large files so are quite often hard to send and download.

Vector files are created in professional design programs, and they are a completely lossless file type that can be scaled to any size without loss of quality. For example, vectors are ideal for logos so they can be scaled up and down with ease. Vector files are quite often saved from Adobe Illustrator in the native AI format, but can also be saved as EPS files too.

Bitmap and GIF files are low quality files used on the internet and are therefore not suitable to print from.

There will be a more in depth breakdown of file types in a few weeks time.


Image Resolution

When talking about a ‘raster’ image - which is an image made up of pixels (any photo you take on a camera, or image captured by a scanner) - the main concern is the resolution of the image. Resolution is measured by how many pixels per inch (PPI) the image contains. You may have heard the terms 72dpi or 300dpi before. DPI actually stands for dots per inch and is meant to describe the number of dots a printer is capable of putting down onto the paper, not how many pixels are in an image. However, it has become the common way of describing resolution instead of PPI. We’ll stick with the correct terminology!

An example of how pixels per inch work and how it effects how an image displays.

An example of how pixels per inch work and how it effects how an image displays.

72ppi images are suitable for on-screen display, as they are generally lower quality because they contain fewer pixels. However, a lot of digital cameras capture images at 72ppi, even when they are set to their highest quality. This is because the actual file itself is about 1000 x 700mm in size, so it is a huge physical image, but doesn’t have many pixels per inch at this size. A simple conversion in Photoshop to 300ppi makes the image 240mm x 168mm. This is the true, high resolution ‘printable’ size of the image.

We’ll divulge more information on Image Resolution in the coming weeks.


Printing Methods

There are many different ways of getting ink on paper, and we humans have been doing it for thousands of years. Without getting too much into the history of printing, and every printing method available, there really are a two mainstream methods used today.

A cross-section type look at how an offset press works.

A cross-section type look at how an offset press works.

Offset printing, also known as Offset Lithography or Litho Printing, is the most common way to print items such as business cards, letterheads, newsletters, postcards and flyers. It is cost effective on medium and long runs and is a high quality, versatile method of printing. The concept behind offset printing is that oil and water don’t mix, so the image area of a printing ‘plate’ attracts the oil in the ink, whilst the non-image area is wet, and repels the oil-based inks. This plate is then pressed onto the surface of the substrate.

Digital printing has emerged in the last 20 or so years as the newer, more popular way to print. Digital printing is produced on either a inkjet or laser printer, where the image to be printed is sent directly to the printer via a digital file (like a PDF). This eliminates the need for a plate, so the cost savings are huge for smaller runs. Digital printing can be expensive once larger runs are needed, as the costs are fairly fixed, unlike offset printing which has large setup costs, but minimal costs once it is underway.

Other methods of printing like Screen Printing, Flexography, Pad Printing, Letterpress Printing and more will be discussed in a few weeks time.

In conclusion to today’s post, we’ve just scratched the surface on a few of the major topics to do with printing. Over the next couple of months, we’ll release a dedicated post on each of the points covered today, with more detailed information. The design and print team at Left Bank Gallery - myself (Toby), Michelle and Julia, are well experienced in all things print. I’ve worked as a print designer for 12 years now, and have been running small and large format printing machines here in our Southport workshop for around 6 years. Contact us today to discuss how to setup your files for printing or for any general design and print advice.