Will having too little Ink resin affect the glossiness?

　　Yes,Ink resin content in the ink will significantly affect gloss.Resin is one of the most critical factors influencing ink gloss.

Firstly, from the perspective of film-forming mechanisms, ink resin is the cornerstone for building a smooth and glossy ink film.

The essence of gloss is the surface's ability to specularly reflect light. The smoother and more level the surface, the stronger the specular reflection and the higher the gloss. After solvent evaporation or chemical reaction, ink resin can form a continuous, dense, and transparent film. If the system contains a sufficient amount of ink resin, it can effectively wet and evenly spread over the substrate surface. Through excellent leveling properties, it eliminates defects such as ripples or orange peel generated during printing, forming a mirror-smooth layer. Conversely, when there is too little ink resin, the ink film cannot form a complete, continuous coverage. Its surface becomes rough, porous, and may even develop cracks. When light hits such a microscopically uneven surface, a large amount of diffuse reflection occurs, reducing the intensity of light reflected in a concentrated direction. The direct manifestation is a substantial decrease in gloss, making the printed product appear dull, lifeless, and lacking vitality.

Secondly, regarding the fixation and distribution of pigments and fillers, ink resin plays the crucial role of "encapsulation and positioning."

Pigment particles themselves do not possess film-forming capabilities; they need to be fully encapsulated and bonded by ample ink resin. This is not only to firmly adhere the pigment to the substrate but also to stabilize the spatial distribution of pigment particles during the drying process. When the proportion of ink resin in the formulation is insufficient, the encapsulation of pigments (especially those with high oil absorption) and fillers becomes inadequate. In the early stages of drying, the stability of the dispersion system decreases, making pigment particles prone to flocculation and forming microscopic agglomerates that disrupt surface smoothness. During drying, pigments of different specific gravities may also undergo selective migration due to insufficient restraint from the resin—for example, heavier carbon black sinking and lighter organic pigments rising—causing "floating" or "flooding." This uneven distribution creates inconsistencies in the composition and texture of the ink film at a microscopic level, severely interfering with the uniform reflection of light. This is a key reason for uneven gloss and overall gloss reduction. Therefore, selecting an appropriate type and amount of ink resin that matches the pigments is a prerequisite for achieving high gloss.

Furthermore, the inherent physicochemical properties of the ink resin itself directly determine the potential for gloss. 

 Different types of ink resin, such as polyurethane, acrylic, rosin-modified resins, etc., vary in molecular structure, molecular weight distribution, transparency, cohesive energy, and curing shrinkage rate. Some specially designed high-gloss ink resins exhibit excellent leveling, high transparency (to avoid absorption of light by the resin itself), and flexibility (to reduce surface deformation caused by shrinkage). Even at the same dosage, high-performance ink resin can deliver superior gloss. Conversely, if the ink resin used has poor film-forming properties, low transparency, or poor compatibility, increasing its amount may have limited effect on improving gloss or even introduce other negative issues. This indicates that attention must be paid not only to the "quantity" of ink resin but also to its "quality."

However, the role of ink resin must be viewed within a systematic framework, as gloss is the result of the synergistic interaction of multiple factors.

Although ink resin is core, other components and process conditions cannot be ignored. For example, the particle size and dispersion of pigments: ultra-fine and well-dispersed pigments require more precise encapsulation by the ink resin to realize their potential for enhancing gloss. The influence of additives is more subtle: wax additives added to improve surface properties can slightly reduce gloss, while excessive defoamers or dispersants, if incompatible with the ink resin, may disrupt the continuity of the film layer. From a printing process perspective, highly absorbent substrates (like newsprint) quickly absorb the low-molecular-weight components of the ink, causing the ink resin to be fixed before it can fully level, making it naturally difficult to achieve high gloss. In contrast, low-absorbency substrates (such as metallized film or high-quality coated paper) provide a platform for the ink resin to fully level and form a smooth surface. Additionally, ink film thickness, drying speed, and method (e.g., UV curing sets instantly, placing extremely high demands on the balance between leveling and curing of the ink resin) all interact profoundly with the performance of the ink resin.

In summary, the content and properties of ink resin are indeed the lifeline affecting gloss.

Insufficient ink resin in the formulation directly leads to film-forming defects and uneven pigment distribution, stifling the possibility of high gloss at its physical foundation. When addressing insufficient gloss on printed products, after confirming the substrate and printing process are correct, the ink resin system within the ink formulation should be examined first—is the amount sufficient, is the appropriate type selected, is it well-matched with other components? Scientifically optimizing the selection and proportion of ink resin is one of the most direct and effective technical paths to achieving the desired gloss. This is not merely a formulation technique but also a reflection of a deep understanding of the science of printing materials.