paragraph space after spacing doesn't appear to be accurate? Illustrator CS6

Question

I have some type which I have created a space after in the paragraph settings. I wanted the space after to be 0.3cm so I have entered that in which converts to 8.5pt.

However when I create a box with the same height of 0.3cm which converts to 8.504pt more or less the same there is a big difference in the spacing

The black box indicates the height of 0.3cm I am not sure what is going on. The black line is a dashed line ive added within the text box that does not have any paragraph settings added to it.

To give context I have attached an image of what I am trying to do and my update in progress so far. So now I have I guess simulated a baseline grid in illustrator of 0.3cm and using the space after paragraph to shift the lines of text to line up to this grid. I have the hierarchy of header, subtitle and body copy and they are all in the same text box so I am using the space after to create even spacing between them. If there is a better method in doing this it would be good to know :)

Answer 1

Paragraph space before/after only works on multi-line type objects. The space is inserted between the baseline and the ascenders of two lines of type.

It won't display anything on a single line of type. In fact, it will appear completely nonexistent one a single line of type.

Its important to realize it is a type setting. If there's no type which requires the spacing, it's not inserted and the baseline indicator for the type object doesn't move. -- It's not some sort of "padding" setting for the object itself.