It is common to add a separate page with statements to the dissertation. This is, as it were, the core of the defense during your promotion. The statements ask for a different format than the dissertation itself.
The outsourcing of the design of the propositions has the advantage, like the bookkeeper, that all the printing around your promotion has the same style and appearance. A graphic designer ensures that the formatting and layout are appropriate for the statements, but at the same time integral with the rest.
Design propositions yourself
When you get started with the statements, keep in mind that you need to adjust the resolution, font embedding and formats. It is the biggest challenge to put the statements in a clear way while keeping the same style of the other print.