What are the advantages and disadvantages of a CIELAB colour workflow?
A. I see two problems with an L*a*b* workflow. The first is that the use of a standard colour encoding space has the disadvantage that it needs multiple colour transforms. With 8 bit data this leads to precision issues at each conversion. With L*a*b* this is accentuated by the fact that less than half of the encoding values are used which effectively means reducing 32 bits to 29 or 30 bits of data. On the plus side since L*a*b* is a (approximately) perceptually uniform space it will be acceptable for many applications, but contouring remains a risk. The second problem relates to elements that you want to define as particular . Converting CMYK images to CIELAB should be OK providing you take care in selecting the rendering intent. The most likely problem is that you can expect ‘pure’ ink colours to be returned with small dots of other colours when you re-separate them. So a pure cyan, for example, may come back when converted back to CMYK with 1 or 2% dots of other colours. This depends
