Stratasys Rigur Transparent PolyJet 3D printing polymer combination is defined by a two-component digital material configuration in which the primary resin is RGD720 transparent rigid photopolymer and the secondary resin is VEROBLACKPLUS RGD875 black rigid photopolymer. In multi-material PolyJet systems, the print heads deposit controlled droplets of both resins in a single layer, followed by in-line UV curing. The resulting material occupies a design space between fully transparent RGD720 and fully opaque VeroBlackPlus RGD875. The primary phase establishes the continuous acrylate network; the secondary phase contributes opacity, neutral-dark coloration, and localized changes in light absorption. The material is intended for functional prototypes, translucent housings, visual flow models, optical shadow-mask components, and engineering verification where a gradient or smoked aesthetic must be combined with rigid photopolymer behavior. Build specifications depend on the selected jetting platform: systems in the Stratasys J-series and Connex-series use 0.016 mm to 0.030 mm layer thickness settings, and support material is assigned to overhangs and cavities. The combination is processed without machining of a solid block; therefore mechanical properties are anisotropic, with lower elongation typically observed in the Z direction than in the X-Y print plane. This anisotropy follows layered UV cure and must be considered when quoting tensile values from datasheets, which normally report specimens printed in the X-Y orientation.

What separates the RGD720/RGD875 digital blend from single-resin VeroClear and VeroBlackPlus materials?

The distinction is not merely optical. A single-resin VeroClear or RGD720 part has a homogeneous refractive index and cure conversion profile, whereas the digital blend alternates voxel populations of clear and black resin within the printed solid. At low secondary loadings, the continuous clear phase dominates tensile modulus and glass transition; at higher loadings, the black secondary phase increases light absorption and reduces luminous transmittance but does not transform the material into a high-temperature engineering polymer. Published single-resin datasheets for rigid PolyJet materials show tensile strength in the range of 50–65 MPa for the transparent base and 50–60 MPa for the black base when tested per ASTM D638-14. Elongation at break typically falls between 10 % and 25 % for both resin families, while flexural modulus is near 2000–2500 MPa. The digital blend’s exact values are ratio-dependent and may be lower than either neat resin in the Z orientation because the multiple jetting heads can introduce weak interfacial boundaries between clear and pigmented droplets. Compared with Digital ABS Plus, the Rigur Transparent combination lacks the high heat deflection temperature associated with ABS-like PolyJet materials; its upper service temperature remains near the glass transition of the base acrylate network, commonly around 45–50 °C under load. Compared with an opaque rigid black material, the presence of RGD720 reduces optical density and permits inspection of internal features.

Tensile, flexural, and impact data generated for the base resins under laboratory conditioning at 23 ± 2 °C and 50 ± 5 % relative humidity provide only an envelope for the digital combination. For design calculations, specimens should be printed flat on the build tray with a minimum of four replicates and tested in both X-Y and Z orientations according to ASTM D638-14 and ASTM D790-17. Izod impact values for neat rigid PolyJet materials are typically in the 20–30 J/m range, but the mixed material may exhibit lower notch sensitivity when the secondary phase is below a threshold; published data for this specific configuration is limited. Moisture absorption under ASTM D570-98 can reach about 1.0–1.5 % by mass after immersion, which is relevant for parts exposed to humid or wet service. Dimensional changes due to moisture are generally below 0.2 % for short-term exposure, although thin sections may curl if one side is exposed to liquid while the other remains dry. The table below summarizes property envelopes for the two base resins, not the fully formulated blends, because the blend ratio is selected in the printer software and is not disclosed by the manufacturer as a single fixed compound.

Screened optical density windows versus impact response in transparent-to-black gradients

Light transmission in the mixed system is governed by absorption and scattering rather than by refractive index alone. The neat RGD720 phase can be tested for total luminous transmittance and haze according to ASTM D1003-13; a transparent PolyJet material typically shows transmittance above 80 % for a 2 mm thickness after polishing or coating. The addition of VEROBLACKPLUS RGD875 reduces transmitted light sharply as secondary mass or volume fraction increases, and the material enters a visually opaque regime at relatively low secondary content because carbon-black pigmentation has high absorption across visible wavelengths. Users who require inspectable internal flow paths or light-pipe evaluation should specify the lowest secondary loading that provides sufficient contrast. At higher secondary loadings, the material approaches the optical performance of VeroBlackPlus RGD875, and transmitted light measurements become less meaningful than reflectance and color coordinates. The mechanical consequence of pigment loading is linked to stress concentrations around dispersed pigmented domains. In impact loading, a highly pigmented PolyJet part may show reduced elongation at break and a greater tendency for crack propagation along layer interfaces. Empirical process data from production-scale PolyJet lines indicate that mixed transparent/black jobs can show color streaking if the secondary resin is not uniformly jetted after idle periods; purging the print heads with the manufacturer’s cleaning cycle is recommended before long builds. This is a maintenance boundary rather than a resin fault and is more apparent when the digital blend gradient contains adjacent clear and near-black voxels.

On Stratasys J-series systems such as the J850 Prime or J826, the RGD720 and RGD875 cartridges are loaded into separate material channels, and the digital material ratio is assigned in GrabCAD Print or PolyJet Studio. Build speed, surface finish, and tensile anisotropy are influenced by the print mode; High Speed mode uses a wider layer interval and may reduce surface gloss, while High Quality mode uses a narrower interval and improves fusion between droplets. The support material, typically SUP706, is a water-soluble photopolymer that is removed in a dedicated water-jet station. Thin walls and small-diameter channels below 1.0 mm may fracture during support removal if the jet pressure is not reduced; post-processing technicians commonly maintain pressure below 6 bar for fragile clear sections, although the safe pressure depends on wall thickness and drain design. Parts should be thoroughly dried after support removal before measuring dimensions or applying an optional clear coat. Unprotected RGD720-rich surfaces can absorb moisture and may exhibit a slight loss of tensile modulus in humid environments above 60 % relative humidity. The manufacturer’s safety data sheets and process guidelines should be followed for uncured resin handling and waste disposal.

When secondary RGD875 loading shifts jetting viscosity and pigment suspension stability

The two base resins are designed to have similar jetting viscosities, but the addition of black pigment in RGD875 can modify the non-Newtonian behavior of the secondary stream. PolyJet print heads operate with heated reservoirs typically in the range of 70–75 °C to reduce viscosity to a printable range; if the secondary cartridge is colder than the primary cartridge at the start of a job, the black resin may jet with a different droplet volume, producing an unintended concentration gradient. This is most visible in large flat panels where the first printed layers appear darker or lighter than subsequent layers. Production-scale systems therefore use print head service routines that bring both material channels to thermal equilibrium before printing. Pigment suspension stability in RGD875 is normally maintained by cartridge agitation or circulation; settling is not typical in factory-filled cartridges, but aged cartridges stored beyond the manufacturer’s shelf-life may show increased optical variability. The risk of cure-depth mismatch increases when the secondary fraction is high because carbon-black can absorb UV radiation and reduce the depth of cure in the black voxels. If the UV dose is not adjusted, thick black-dominant regions may show lower conversion at the bottom of the layer, leading to lower transverse tensile strength and delamination. This is a process cliff-edge: beyond a formulation-specific secondary content, the standard UV exposure may be insufficient for full layer-to-layer adhesion. Published data for this specific configuration is limited, but the failure mode is consistent with UV screening by black pigments in acrylate photopolymers. When printing near-black digital blends, the operator should verify layer adhesion with a simple peel or tensile test before committing to large batches.

Chemical resistance, solvent exposure limits, and sterilization constraints

Rigid PolyJet photopolymers based on acrylate chemistry have moderate resistance to water, weak acids, and weak bases, but they are susceptible to swelling or stress cracking in ketones, chlorinated solvents, and strong alkalis. The RGD720/RGD875 blend is not chemically equivalent to polypropylene and should not be used as a direct chemical resistance surrogate for injection-molded PP. Exposure to ethanol or isopropanol can cause surface hazing on transparent RGD720-rich areas if contact time exceeds a few minutes; manufacturer guidance typically recommends neutral aqueous cleaning solutions. The material has no implicit food-contact or biocompatibility certification; compliance requires grade-specific documentation against the target regulation. Under RoHS Directive 2011/65/EU, the base resins are not known to contain restricted heavy metals above threshold limits, but the user must confirm via the safety data sheet. Under REACH Regulation (EC) No 1907/2006, SVHC content and registration status are substance-specific; no blanket statement applies to the mixed digital material. For medical device builds, ISO 10993-1:2018 testing would be required on the final printed and post-processed part because the surface chemistry differs from the bulk liquid resin. Steam autoclaving is not recommended for standard PolyJet rigid materials because service temperatures exceed the heat deflection temperature; low-temperature hydrogen peroxide or gamma irradiation may be considered only after validation.

Application examples for the RGD720 primary/RGD875 secondary combination include translucent instrument covers with opaque labeling zones, fluidic manifolds where internal channels must be inspected during development, architectural scale models requiring smoked glazing, and consumer electronic prototypes that combine light pipes with black masked areas. The material is also used in automotive lighting trial parts when the build tray must produce a single component with different optical densities in the same build, avoiding the need for painting or assembly. Functional performance in these applications depends on controlling secondary content, print orientation, and post-processing. Parts printed in the X-Y plane exhibit higher tensile strength and elongation than those printed in the Z plane; features intended for repeated assembly should be oriented with load-bearing axes in the X-Y plane. Threads and snap-fits made from this class of photopolymer may degrade under cyclic loading, and creep deformation under continuous stress is more pronounced than in filled engineering thermoplastics. Therefore design validation should include the specific digital material ratio and not rely solely on published data for the neat RGD720 or RGD875 resins. Published data for this specific configuration is limited, and production users are advised to generate internal property datasets using the equipment and post-processing route intended for serial output.