Due to sustainability demands, namely, to reduce the CO2 emissions and environmental footprint, textile printing with natural dyes and ingredients has emerged as an appealing alternative to fossil-based solutions for textile printing. The widespread use of natural printing coloration using wastes is still challenging due to their availability and lack of knowledge regarding the transformation processes for application, formulations and final performance. This article explores the incorporation of residues, namely ash from biomass boilers, as an alternative to synthetic colouration, into innovative biobased printing paste applied to cellulosic textiles (cotton). The research focused on developing a biobased printing paste while adapting residues to ensure their compatibility with this formulation and traditional printing processes. Mechanical micronisation of the residues by ball milling under various conditions, was explored to achieve suitable particle size and shape for textile printing applications. Based on the research and development previously carried out at laboratory scale, an industrial pilot trial was performed, where printing applications and demonstrator products for the home textile sector were produced. The demonstrator has shown good results in terms of performance and durability, including colour fastness to washing, to artificial light, to rubbing, to water, to perspiration and to artificial saliva. By converting waste into valuable resources, this biobased printing paste not only meets industry demands for performance but also paves the way for a more sustainable future and contribute significantly to the EU’s goal of achieving climate neutrality by 2050.