Can't picture the result or desired outcome. I might be stymied by your use of the word line in what seems to be more than one context, meaning I'm not sure when it means a line of text in a control, a record row in the report or what.
it is important that each page of the report shows the same overall number of lines
If this means records, I don't see how it's possible given that some records seem to have expanded textbox height due to the number of lines within the textbox. This means that some records on page one could be, for example, 2" tall while others are only .50 tall, while on page two, all are 2" tall. There's no way to get the same number of "lines" on each page if lines means records.
Furthermore, your post title suggest it is the spacing between lines you are after, not the number of lines on a report page. If that's the case, it's governed by the amount of space below the bottom most row of controls for a record and the next divider - be that a grouping section or footer.
Last edited by Micron; 07-14-2017 at 01:13 PM.
Reason: added info
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.