The ability of food hydrocolloids to engineer flow, structure, and lubrication makes them indispensable in next-generation food design. This study investigated the role of xanthan gum (XG) in modulating the 3D printability, rheological behaviour, structural features, and attributes of formulations prepared from heat-desiccated milk solids (HDMS) added with cane sugar. XG was incorporated at 0.5, 1.0, and 1.5% (w/w) in HDMS with total solids (TS) of 55 and 60% and cane sugar concentrations of 20 and 30% and were examined for rheological, tribological, thermal, and microstructural characteristics in relation to 3D printing performance. XG addition significantly elevated viscosity, storage modulus (G′), yield stress, and shear recovery, collectively underpinning enhanced filament continuity and self-supporting capacity during extrusion. Thermal sweeps confirmed stability of these entangled networks under processing-relevant temperatures. Tribological measurements revealed reductions in friction coefficients across sliding regimes, suggesting improved oral lubrication and smoother bolus formation, attributes of direct relevance for dysphagia-oriented diets. At the molecular scale, FTIR spectra indicated a progressive α-helix to β-sheet transition within protein domains, while ^1H NMR revealed restricted water mobility arising from protein–hydrocolloid entanglement. Differential scanning calorimetry highlighted XG-induced glass transition depression and elevated ΔCp, consistent with water-binding and plasticization effects. Microstructural imaging (SEM, CLSM) corroborated these findings, showing denser, homogeneous protein–polysaccharide networks in XG-enriched formulations. Texture profile analysis further aligned with these structural modifications: increased hardness, cohesiveness, and chewiness were evident in gum-rich constructs, several of which satisfied International Dysphagia Diet Standardisation Initiative (IDDSI) Levels 5–7. Notably, the formulation comprising 60% HDMS, 20% sucrose, and 1% XG exhibited the most favourable balance of extrusion flowability, dimensional fidelity, and textural suitability. Collectively, these results demonstrate that deliberate modulation of hydrocolloid–protein interactions afford precise control over the physical properties that underpin printability, lubrication, and structural stability. By defining an optimal compositional window for XG, this work advances a framework for exploiting hydrocolloids as design tools in extrusion-based 3D printing of dairy products. Beyond immediate applications in dysphagia-friendly foods, the findings underscore the broader potential of hydrocolloid-mediated structuring to accelerate the development of customizable, nutritious, and consumer-oriented 3D printed food products.