3D Systems VisiJet RBK-RWT-L20 Multi-Material Composites (VisiJet CR-BK + VisiJet CR-WT 200**) is a paired rigid photopolymer feedstock system for MultiJet Printing platforms configured for two build materials and a separate support material. The product is not a pre-mixed composite resin; “composite” in this context refers to a multi-material build arrangement in which VisiJet CR-BK and VisiJet CR-WT 200 are deposited through separate piezoelectric printhead channels. This allows rigid black and rigid white regions to form in one monolithic cured part without secondary bonding, overmolding, or manual assembly. The L20 identifier refers to the supplier’s cartridge-bundle format rather than a filler or reinforcement package. Typical applications include functional prototypes, visual verification models, master patterns for tooling, and short-run models where black-white contrast must remain stable under low-to-moderate mechanical load.

The two resins are UV-curable acrylate formulations supplied in sealed cartridges. Processing is governed by the MJP build profile, which commands printhead temperature, jetting waveform, roller engagement, layer thickness, UV irradiation, and support-material deposition. In standard high-definition mode, the platform builds at a layer thickness of 0.032 mm; finer modes may be available depending on the specific machine and job definition. A planarizing roller removes excess liquid from each jetted layer before the UV lamp cures it. For a two-material part, the roller does not distinguish between black and white fluid; it removes local excess and can carry a small residual film across the black-white boundary. Boundary sharpness is therefore not controlled by drop placement alone but by the interaction of wet-fluid rheology, roller speed, and cure timing.

What separates the RBK-RWT-L20 pair from a single-grade rigid MJP feedstock under production conditions?

Single-grade MJP parts contain only one build-material-to-support interface. The RBK-RWT-L20 set adds a second, persistent build-material-to-build-material interface between black and white regions. That interface is formed layer by layer and is influenced by the viscosity difference between the pigmented formulations and the degree of interpenetration that occurs before UV cure. On MJP 5600-class equipment, the black material often exhibits a slightly lower viscosity at jetting temperature than the white 200 formulation, but batch-to-batch variation in pigment dispersion can invert this relationship if cartridges are not conditioned or if printhead channels are partially degraded. Published viscometry data for this specific formulation combination is limited; process transfer from one machine to another should be confirmed by printing a two-material transition test coupon rather than a monomaterial part.

Because these are cross-linking photopolymers, ISO 1133-1:2022 melt-flow testing is not applicable. The relevant uncured-fluid property is jetting viscosity, measured by rotational rheometry such as ASTM D4440-15 or a cone-and-plate method at the printer jetting temperature. The MJP printhead can tolerate only a narrow viscosity envelope; cartridges that have exceeded their recommended shelf life or have been exposed to ambient UV can drift outside that envelope and produce missing jets, curved traces, or local thickness variation. Cartridges should be stored away from sunlight and blue-rich LED sources and equilibrated to the printer room temperature before insertion. The black and white feedstocks must not be blended in a bulk container or cartridge; the system relies on separate fluid pathways to maintain visual contrast and to prevent an uncontrolled gray mixture that can shift local cross-link density.

Mechanical-property benchmarks for CR-BK and CR-WT 200 under ASTM D638-14, ASTM D790-17, and ASTM D648-16

Representative published datasheet values for the two rigid grades show a consistent stiffness difference. VisiJet CR-WT 200 is typically reported with tensile strength in the 42–46 MPa range and tensile modulus in the 1.6–1.9 GPa range when tested to ASTM D638-14. VisiJet CR-BK is typically cited in the 32–38 MPa tensile-strength range with tensile modulus in the 1.3–1.6 GPa range. Elongation at break is usually higher for the black grade, often in the 13–20% range, while CR-WT 200 sits at the lower end of that band. Flexural modulus values under ASTM D790-17 follow the same ranking. Both grades exhibit heat deflection temperatures under 0.455 MPa loading in the 45–52°C range when tested to ASTM D648-16, so neither material is suited to elevated-temperature load-bearing service. Notched Izod impact values from ASTM D256-10 are in the low-to-mid 20–35 J/m range, which is lower than typical unfilled polycarbonate or PA12 and should be considered for snap-fit or impact-prone features.

In production builds, the most commonly observed multi-material defect is not bulk delamination but a cosmetic feather zone at the black-white boundary. The feather zone is a gray transition band produced when the planarizer carries residual black liquid into the white region, or vice versa, before the UV array cures the layer. Field data from MJP equipment indicates that transition lines oriented parallel to the planarizer travel direction are more stable than transitions oriented normal to roller travel. A worn planarizer blade or degraded wiper increases the transition-zone width beyond the nominal voxel pitch even when the jetting channels are otherwise healthy. Because the bulk mechanical properties of the two grades are similar, the boundary defect usually has a larger impact on visual contrast and downstream tooling than on tensile or flexural performance. When the part is used as a master for silicone tooling, the boundary defect can replicate in the mold surface and should be evaluated under 20× magnification before mold-making.

When the support-removal cycle exposes rigid black and rigid white surfaces to thermal and solvent-cleaning loads

The RBK-RWT-L20 set is processed with a separate support material, typically the platform’s wax or wax-like support system. Support removal uses a heated oven or bath followed by a milder cleaning stage in an ultrasonic unit or supplier-approved solvent-free detergent system. The process window has two constraints. First, the support-removal oven temperature must remain below the heat deflection range of both rigid materials. If the oven setpoint rises into or above the 45–52°C range while the part is under mechanical load from support tooling or orientation, thin white sections may creep and black-white edge definition can be lost. Second, residual support wax can wet the pigmented black surface differently from the white surface; incomplete removal often appears as dark spots or a cloudy film concentrated at the boundary. Cleaning fluids should be qualified on a two-material coupon, not on a monomaterial coupon, because the presence of two pigments can alter surface-wetting behavior at the transition. Published data on repeated ultrasonic cleaning of this specific black-white interface are limited, so the number of cleaning cycles should be minimized until lot-specific results are available.

Compared with other VisiJet rigid materials, CR-BK and CR-WT 200 are selected when the build must show black-and-white part identity without post-painting. They do not replace VisiJet CR-CL clear rigid material for optical or light-transmission prototypes, and they are not interchangeable with VisiJet CE-BK, which is an elastomeric black formulation for flexible parts and soft-touch features. Compared with the VisiJet M2R series used on other MJP platforms, the CR-series feedstocks are matched to different printer profiles, support systems, and cartridge formats; cartridges should never be moved across incompatible platforms without a firmware-level material check. In relation to powder-bed PA12 or PC-based thermoplastics, the RBK-RWT-L20 set has lower notched impact energy, lower heat deflection temperature, and greater sensitivity to long-term UV exposure. However, the MJP process is capable of resolving small features, smooth vertical walls, and precise two-color boundaries at a 0.032 mm layer thickness, which is frequently more critical for visual prototypes and master patterns than the higher toughness of SLS or injection-molded resins.

Chemical compatibility is limited. The cured network should not be soaked in strong solvents such as acetone or methylene chloride, and aggressive industrial cleaning agents should be evaluated by ASTM D543-20 before deployment. The materials are supplied as industrial photopolymers; they are not automatically certifiable for medical device or food-contact use. No statement of USP Class VI, ISO 10993-1, or FDA 21 CFR 177 suitability should be inferred from the base resin classification or from the term “composite.” Each application must be verified against the current lot-specific certificate and safety data sheet. For disposal, users should apply the waste codes listed in the SDS rather than handling uncured resin as an ordinary non-hazardous liquid. Operators should also observe the minimum cartridge conditioning time after cold storage; loading a cartridge at the low end of the storage range can increase fluid viscosity and produce missing jets until the cartridge reaches the jetting setpoint.

Production-scale failure modes on MJP equipment are dominated by printhead nozzle degradation and cartridge handling rather than by the bulk material properties. A partially clogged nozzle can produce local thickness variation that becomes visible as a ridge at the black-white boundary because the roller removes more or less fluid from one pigmented region. Cartridge lot changes should be recorded, because subtle shifts in pigment dispersion or inhibitor concentration can alter jetting viscosity and the resulting boundary feather width. For multi-shift operations, a standard first-article inspection should include a two-material coupon with horizontal and vertical boundaries, flatness measurement after 24 h on a surface plate, and dimensional audit to the platform’s stated tolerance, typically ±0.1% or ±0.1 mm for a well-characterized build. If the coupon passes, the full build can proceed with reduced risk of boundary-related rework.