I love Amazon, this hardcover book only sold 16.96 USD on Amathon Australia. this is the cheapest tool I have ever bought for my designer career, but vitally necessary.
Without this book, it is really hard to ensure the colour accuracy of the prints. Especially, I am a fun of RGB color system as I do digital design more, so what comes on screen I want it to be exactly the same appears on the prints.
It said that people don't have OCD cannot be a designer. I know that is a joke, but it reflects what a designer believes. Although sometimes we need to compromise on the customer's requirement, perfect is still our ultimate goal.
I know some people just keep asking that, is it really matter of one pixel or one bit of colour different? The true thing is that in almost all cases of design, people even don't notice that there are differences as they cannot see it through the eye. However, my answer is that once you have broken your rule, you can keep going on with the same standard anymore.