Artwork Tips
We receive so many discs each and every day, the majority of which produce files which we can print from without any problems. Occasionally though we get files which do not print as intended and are not what you, the customer, expected. This guide has been compiled to assist you with the stages of designing and setting up your files for print. It'll go a long way in helping you avoid extra costs incurred, by us trying to rectify your files.
colours
Spot Colours
When
choosing different colours for your job, try to choose colours from the
Pantone© colour palette if your software has it. If the job you require
is to be printed in process, make sure these colours are converted to
their CMYK equivalent. If your job is to be printed with a spot colour,
check to make sure you have just one version of the spot colour. Some
packages will have a CV or a CVC version of the same colour. A good way
to check how many colours you have in your document is to print separations
on your desktop printer. If you have more than the required number of
sheets out of the printer, then you have too many colours.
RGB to CMYK
Your scanner, digital camera, computer and
monitor use a combination of three colours: Red, Green and Blue (RGB)
to create images. The printing process uses four colours to print the
same images: Cyan (light blue), Magenta (cerise), Yellow and Black (key
colour), commonly referred to as CMYK or process colours. At some stage
the production workflow all RGB images have to be converted to CMYK.
The conversion from RGB images to CMYK should be done before the file
is sent to us in an image manipulation package like Photoshop. If this
conversion is not done there is a danger that the standard RGB to CMYK
conversion profile we use may make some of the colours appear to be washed
out or dull.
Black isn't really Black
You
may not realise, but a lot can be done with black to help you to achieve
the desired results. To get the best from our process, black can be produced
in two ways. The first method is single colour black, made from 100%
black ink. This is ideal for small areas such as text.On larger areas
of black solid single colour black can often appear grey or washed out.
The way to achieve a dense black on large areas of black solid is to
print a 40% Cyan underneath the 100% Black. This will give an even and
dense colour as the second colour disguises any inconsistencies.
Set-off
Set-off is the marking of the underside of a sheet
by the transfer of ink from the sheet on which it lays. It can occur
when pressure is applied during guillotining or simply while the Substrate
is stacked. Set-off is caused by the fact that the ink is still wet,
and is most prevalent on uncoated stocks. Set-off shouldn’t happen if
you are careful about the weight of colours you pick. We have set some
guidelines to help you avoid set-off or lengthy drying times. Our recommended
ink coverage limit is 225%. This means that, wherever possible, the colours
you use should contain less than a total of 225% when you add together
cyan, magenta, yellow and black.
Proofing
As part of our service, you
have the option for us to supply you with a colour proof. If this is
mentioned in the origination section of your estimate from us, then it
is included. If not, for peace of mind, you may wish to request a proof.
The proof is produced on our high-end colour inkjet printer which has
been profiled to best match our machinery. The proof is not 100% accurate
and is meant as a fairly accurate guide as to how your job will look.
Images
If you are scanning photographs yourself, save
them as either EPS or TIFF files as this will preserve the colour and
clarity of your images. If you are scanning a previously printed item,
such as a magazine photo, you will need to ‘de-screen’ the image, blurring
it slightly to avoid a moiré effect. GIF or JPEG formats compress the
image and actually discard information, causing colour shifts and blurriness.
Don’t use either of these file formats – they may actually print in black
and white and you won’t like the results.
When you are scanning, consider the final size that your image will be
used at. Always scan photographs at 300dpi at the size you are going to
use them. There’s no point scanning a postage stamp at 300dpi and then
blowing it up to A4 size – use your scanning software to help you calculate
the output resolution. Conversely, scanning photographs at more than 300dpi
will have little or no effect on the actual printed quality and will unnecessarily
increase file size and processing time. Don’t enlarge/reduce your scanned
images in your drawing/vector software (such as Illustrator) – it’s always
best to use an image-editing application such as Photoshop for this task.
When converting photographs from RGB to CMYK, In the ‘edit’ menu choose
‘colour settings’. From the window that appears, choose ‘custom CMYK’ from
the list in the ‘CMYK’ section of ‘working spaces’. Scanning flat or black
and white line art (i.e. a logo), scan this at 800 to 1200dpi for best
results. Any lower, and the logo may appear blurry. Pay careful attention
to the CMYK makeup of any ‘black’ in the logo. The automatically created
Photoshop black, for example, provides 250% ink coverage. You may need
to adjust the colour settings in your application to get a black that is
made from 100% black ink. Make sure that any alpha channels are removed
and all layers are flattened before finally saving your image.