The VisiJet RBK-RCL-L60 Multi-Material Composites package is a two-model-material photopolymer set supplied by 3D Systems for MultiJet Printing equipment configured for simultaneous deposition of an opaque black rigid material and a clear rigid material. The package pairs VisiJet CR-BK, an opaque black rigid photopolymer, with VisiJet CR-CL 200**, a controlled-composition clear rigid photopolymer. The product code does not describe a compounded resin. Instead, the two materials are jetted as separate phases, cured into adjacent voxel domains, and supported by a third, process-specific support phase during layer buildup. The suffix 200** in the clear-component designation appears in manufacturer documentation as a controlled-composition marker, distinguishing the material from earlier CR-CL grades and linking it to batch-restricted quality records. This configuration is specified where one part must combine optically transmissive rigid sections with high-contrast opaque sections—for example, display or cover housings with clear inspection windows, fluidic manifolds with visible channel walls, color-coded anatomical models, and optical sensor housings that require both light-blocking and light-transmitting regions. Because the final part is a multi-material composite and not a blend, the mechanical performance of the RBK-RCL-L60 build is governed by the bulk properties of CR-BK and CR-CL 200, by the quality of the interfacial boundary between them, and by the post-print support removal sequence. The boundary is created repeatedly at every layer and is the dominant source of processing constraints.

Material Format, Printer Compatibility, and Curing Architecture

The package is supplied as two separately identified material containers that are loaded into the MJP system’s material bay. The printer validates container identity, material compatibility, and remaining volume before a build is released. In the build process, CR-BK and CR-CL 200 are heated to a printer-controlled jetting viscosity, filtered through the inkjet fluid path, and dispensed through piezoelectric printheads in layerwise patterns. A separate support material is jetted where overhangs and cavities require temporary placement. UV lamps then irradiate the deposited layer to initiate free-radical photopolymerization. The energy dose is applied in a predetermined pattern that may include additional exposure in areas containing black material, because CR-BK absorbs more light than CR-CL 200. The clear phase transmits UV energy further into the jetted layer, which can produce a deeper cure front and an outward shift in lateral cure near the interface. As a result, the boundary between black and clear domains is not perfectly planar at the voxel scale. The process control parameters that must be held stable include printhead operating temperature, UV lamp irradiance measured by a calibrated radiometer, layer thickness, and jetting frequency. Material specifications for both phases are represented by single-phase test data under ASTM D638 or ISO 527-1 for tensile properties, ASTM D648 or ISO 75-2 for deflection temperature, and ASTM D256 or ISO 180 for impact resistance. These single-phase values do not quantify the strength of the black–clear interface.

The local curing kinetics differ because the photoinitiator system in CR-CL 200 is optimized for optical clarity, whereas CR-BK includes a pigment package that reduces light penetration. At the interface, free radicals generated in the clear phase can diffuse into the adjacent black voxel only if the black phase remains partially unreacted. After gelation, that diffusion is restricted. An overexposure intended to improve CR-BK conversion can create brittle or yellowed clear material. Consequently, the printer’s build mode, material temperature, and UV energy are not independently chosen for each material. They are selected from machine-qualified profiles that balance conversion in both phases. Single-phase datasheet values do not capture this coupled behavior.

Storage conditions for the two component resins follow standard UV-photopolymer practice: upright, light-tight containers in a cool area.

Because CR-BK and CR-CL 200 are jetted from separate reservoirs, the composite is not characterized by a single viscosity or a single density. The fluid path is duplicated for the two model materials, and the material-management system prevents cross-contamination by locking container positions and using material-specific RFID records. Printer-specific cleaning cycles are used when switching between this composite set and other VisiJet grades, because even low-level contamination from a clear material can alter the black pigment dispersion or the photoinitiator balance of CR-BK.

What Limits Support Removal in Multi-Material CR-CL 200 Sections?

Support removal is the most restrictive post-print step for RBK-RCL-L60 builds. Support material is placed adjacent to both CR-BK and CR-CL 200 surfaces. The clear phase is sensitive to the same thermal energy used to melt or soften the support, while the black phase absorbs thermal energy differently. When a convection oven or heated bath is used to remove support, the heating rate must be low enough to avoid a temperature difference between the black and clear domains. A rapid ramp can generate differential expansion at the black–clear interface, which appears as a whitened or reflective zone in the clear material and as a stress riser in mechanical loading. Production-scale support removal often uses a forced-convection oven with a spatial uniformity of ±2 °C or better, and the heating profile is segmented to allow interfacial stress relaxation. Because stress relaxation in the clear phase accelerates above the glass transition temperature, there is a narrow band in which support can be removed quickly without permanent distortion of thin clear features. Process engineers often set the first heating stage below the HDT measured by ASTM D648, then hold at an intermediate temperature to equalize the black and clear domains before elevating to the support melting regime.

Ultrasonic cleaning after bulk support removal is performed at controlled temperature rather than at maximum cavitation power. If cavitation intensity is excessive, the boundary between CR-BK and CR-CL 200 can develop microcavities or the clear surface can lose transparency. Filtration of the cleaning bath is required because re-deposited support particles on clear surfaces form scatter centers. Support material at the boundary can act as a thermal sink or insulator, depending on its phase. If thick support masses are present on one side of a clear wall, the thermal path is asymmetric, causing uneven support softening and local pressure on the part during removal.

Chemical support removal adds a separate compatibility constraint. The clear phase must be screened against the cleaning medium using ASTM D543 prior to production, because ketone- or aromatic-containing solvents can attack rigid acrylate networks and cause surface crazing. Published data for this specific CR-BK/CR-CL 200 pair in alternative cleaning solvents is limited, so process changes are qualified on printed multi-material coupons rather than on single-phase slabs. The final transmittance of clear sections is assessed with ASTM D1003 or ISO 13468-1 after the support removal and polishing steps. The black phase is less likely to show visual residue, but residual support in narrow channels or blind holes is dimensionally significant. Inspection therefore includes transmitted-light examination of clear sections and tactile or optical measurement of black-section cavities.

After support removal, parts are often dried in a light-shielded environment and inspected for interface delamination. Drying is performed below the heat deflection temperature of CR-CL 200 to prevent distortion. Dimensional audits on multi-material parts are more demanding than on single-material parts because shrinkage in CR-BK and CR-CL 200 may differ slightly. A coordinate measuring machine calibrated to ISO 10360-2 is used to verify that the interface does not shift outside the design tolerance. When cracks or delamination at the interface are suspected, dye penetrant inspection according to ASTM E1417 may be used, provided the developer is first screened for optical haze on clear surfaces.

Comparing Rigid Multi-Color Composite Workflows Against Single-Grade and Functional VisiJet Photopolymers

The RBK-RCL-L60 package differs from single-grade VisiJet rigid materials in that it creates a built-in rigid multi-color boundary rather than a homogeneous polymer network. A monolithic CR-CL 200 build undergoes a single cure shrinkage field; adding CR-BK introduces a second phase with different UV absorption, pigment content, and thermal expansion response. This does not make the composite a uniformly stronger or weaker material. The interface must be treated as a design feature. In thin-wall sections, the interface area is large relative to the cross-section, so optical and mechanical performance can become dominated by boundary effects. In thicker sections, the bulk properties of each phase dominate until external loading crosses the black–clear interface.

Compared with sacrificial wax-pattern grades such as VisiJet M2 CAST, the RBK-RCL-L60 package is not intended for investment casting. It leaves a rigid crosslinked photopolymer residue rather than a clean burnout pattern. Compared with flexible or durable photopolymers such as VisiJet CE-BK or VisiJet M2G-DUR, the CR-BK/CR-CL 200 pair is selected for opaque/clear rigid contrast rather than high elongation or repeated flexural recovery. The two rigid grades should not be substituted for elastomeric materials in hinges, snap fits, or sealing elements without mechanical testing. Compared with a post-assembly approach that bonds a separate clear window into a black housing, the multi-material build reduces part count but introduces an interface that lacks the stress-distribution characteristics of a design-level adhesive bond line. The load transfer across the jetted interface depends on the degree of interpenetration achieved before gelation and on the wetting of the second material against the jetted first material. If the first material is substantially gelled before the adjacent voxel is deposited, the interface can have lower bond strength than the bulk values reported for either resin. Therefore, mechanical qualification of load-bearing components should include tensile or shear specimens with the interface located in the gauge section under ASTM D638 or the relevant shear method.

Batch quality assurance for RBK-RCL-L60 builds extends beyond raw material lot release. Because CR-BK and CR-CL 200 are produced and packaged as separate lots, the interaction is lot-pair sensitive. A CR-BK lot with higher pigment dispersion can reduce local cure depth at fixed lamp energy, while a CR-CL 200 lot with different photoinitiator activity can alter boundary gelation. Production-scale users therefore retain paired build records that include printer serial number, printhead age, UV lamp radiometer readings, layer thickness mode, support removal cycle, and cleaning chemistry. These records support an ISO 9001 control plan and allow a batch-related boundary defect to be traced to either component lot or to a post-print variable. When RBK-RCL-L60 parts are used in regulated environments, supplier lot documentation should be linked to first-use date and to the cleaning method applied after support removal.

Inspection of RBK-RCL-L60 parts is divided into bulk and boundary checks. Bulk CR-BK sections are evaluated for hardness, tensile response, and surface finish. Bulk CR-CL 200 sections are measured for transmittance and haze after polishing using ASTM D1003 or ISO 13468-1. Boundary checks include cross-section microtomy and polarized-light microscopy to detect planar voids, incomplete wetting, or shrinkage cracks. Dimensional verification of the black–clear interface is performed on a coordinate measuring machine under ISO 10360-2. If dye penetrant inspection is required for crack detection, ASTM E1417 is applied with a developer that has been screened for clear-surface compatibility. These methods together address the primary failure modes of the composite: bulk-phase property drift, interfacial delamination, and post-print geometry change induced by the support removal cycle.