An Input field would allow end users to add text to a document. The data in the input field is mapped to a variable which could be used to drive the text in a text in chart area of a chart or a separate text box which could be added to the report for printing.
I had a look at the Input Box, but the text that the users want to enter can stretch to more than 2 paragraphs. This then makes it difficult to see the text and the graph on the sheet. I suppose it is a question of user education on how to use it, but something like a text box would make life a lot simpler.