We recently wrote an in-depth article looking at what people new to printing need to know CMYK, which covered the differences between CMYK and RGB. What the post lacked was direction for home designers, who create their own artwork rather than outsource to a graphic designer.
Since around 60% of the artwork that comes through our print studio has been designed by a small business owner themselves, this post covers the CMYK vs RGB issues you need to consider, and how to get round them.
Most desk-top-publishing / graphic design software allow you to set up your artwork in CMYK. This is called 'colourspace' and can be often be found when first setting up your document. If you set the document up in CMYK at the beginning of your design process, elements should be converted to CMYK as you import them, giving you the chance to colour correct items which don't look right (because they've been converted from RGB).
Here's how to set up your colour space in popular programmes:
Publisher defaults to RGB. Use the menu options Tools/Commercial Printing Tools / Colour Printing, and select 'Process Colours (CMYK).
Publisher 2003 - 2007+
Select File > Info > Commercial Print Settings > Choose Colour Model > Process Colours (CMYK).
Select the object(s) you want to convert. Select the 'Fill' tool, and click 'Fill Colour Dialog'. Make sure the 'Color model' is 'CMYK'. Then for every object which has an outline, select the 'outline' tool and click the 'Outline Colour Dialog'. Select 'CMYK' as the 'Colour model'.
Select File > Document Colour Mode > CMYK Colour
Select Image > Mode > CMYK (or select 'CMYK' for the mode when setting up a new file.
Use the following options: Window / Swatches and Window / Colour. Double click 'colour' in swatches, change the colour mode to CMYK and colour type to Process.
Select Edit > Edit Colours > Show Colours in use, then highlight the colour and click edit. Change the model to CMYK and deselect Spot Colour.
There are many colours available in RGB which aren't available in CMYK...
As RGB combines 3 colours, and CMYK four, there are many colours available in RGB which don't have similar alternatives in CMYK. This is called 'out of cmyk colour gaumet'. Generally speaking, RGB colours are far more vibrant than CMYK, which makes images appear faded or 'muted'.