Three-dimensional-printed assistive devices hold promise for improving writing abilities, yet factors influencing device selection and their impact on satisfaction and effectiveness remain unclear, especially in adults, as they are typically tested on children. The aim of this article is to assess the efficacy and satisfaction with a writing assistive device at different angles among individuals with brain injury and explore device selection factors. Twenty-six participants with brain injuries selected their preferred device angle. Writing speed, quality, and satisfaction were recorded. Immediate speed improvements were significant at 5° and 30° (