Monographs have long remained at the margins of the digital and open access (OA) transformation, particularly in Poland and across much of Europe. Unlike journal publishing, the open dissemination of scholarly books has been hindered by factors such as the additional costs of producing professional digital formats (e.g., EPUB) and the enduring perception of printed monographs as more prestigious. This has led many publishers to delay OA release until after embargo periods, limiting accessibility. The implications are particularly significant for the humanities, where monographs are often the primary research output. As a result, humanistic scholarship remains underrepresented in digital databases, reaches narrower audiences, and demonstrates lower impact as measured by dominant bibliometric indicators from major academic platforms. To address these disparities, sustainable OA publishing models tailored to monographs must be developed. This paper presents findings from a mix-method, participatory study of the Polish publishing landscape, identifying key needs, challenges, and opportunities. The study contributes to ongoing debates on open access policies and practices for monograph publishing by offering in-depth insights from one of Europe’s largest academic markets. Its design-driven and scalable research workflow represents an additional contribution, providing a methodological model that can be adapted to similar research contexts.