Proto3000 Objet VeroGray FullCure850 Rigid Opaque Prototyping Polymer is supplied as cartridge designation RGD850. The acrylate-based PolyJet photopolymer cures by ultraviolet exposure during deposition and produces a grey, opaque, rigid thermoset part. Published bulk density after cure is 1.18–1.19 g/cm³ per ASTM D792-20. The product is used for non-transparent concept models, dimensional masters, assembly fixtures, and inspection aids where neutral grey color reduces specular reflection under structured-light scanning. The material is a single-component resin; it does not require mixing or degassing before loading. It is not formulated for continuous mechanical service above its heat deflection limit, and the cured part should not be exposed to prolonged outdoor UV without sealing or clear-coating.

FullCure850 belongs to the rigid Vero resin family and is related to VeroWhitePlus and VeroClear. The product is not an elastomer or a photopolymer replica of ABS. In the jetted state, the resin is processed at nominal layer increments of 16 µm in High Quality mode or 30 µm in High Speed mode. Mechanical property values are print-orientation-dependent; validation specimens should be built in the intended print orientation and conditioned according to ASTM D618-21 before testing. The cured network is stiff and glassy, with published elongation at break in the 10–25% range, which permits rigid snap features but not the high-deflection cycling associated with tougher digital ABS resins.

How Does FullCure850 Compare with VeroWhitePlus and Digital ABS in Standardized Mechanical Testing?

The supplier-published property ranges listed below are generated from specimens built in the XY plane. Values are provided for FullCure850 RGD850, VeroWhitePlus RGD835, and Digital ABS RGD515/535. Because print mode, post-processing, and material lot can shift measured values, comparative selection should be confirmed by a short validation build in the target machine.

The table separates the product classes clearly. FullCure850 and VeroWhitePlus share essentially the same mechanical envelope; the grey variant is selected when the application demands neutral grey opacity and low visible-light transmission, not when tensile margin must be improved. VeroClear is also in the same rigid family but is specified for transparent optics or instrument panels. Digital ABS shifts elongation and heat deflection upward while reducing flexural modulus, making it the reference class for snap-fit parts and higher-temperature service. FullCure850 should not be treated as a drop-in replacement for Digital ABS in live-hinge or high-strain applications.

Cartridge Handling, Jetting Performance, and Failure Modes Seen on Production PolyJet Platforms

On Objet30 Pro and Connex-class machines, RGD850 is fed from sealed cartridges through heated lines to the inkjet print heads. Cartridges should be conditioned to 18–25 °C before loading; a cold cartridge can raise apparent viscosity and produce missing-jet defects that appear as periodic linear voids on vertical walls. Production-scale failure records from PolyJet fleets show that many jetting defects are not resin-lot defects but maintenance failures: dried resin crust on the nozzle plate, wiper drag from contaminated wiper blades, and vacuum leaks at the capping station. The material must be kept away from direct sunlight and unprotected fluorescent UV. Uncured waste and used cleaning materials should be handled according to the supplier SDS. If a head is left uncapped between builds, the exposed surface can skin over and require a longer purge cycle before dimensional work resumes.

Support removal is the largest source of dimensional variation in RGD850 parts. The product is typically paired with a removable support material, and production cells use pressurized water-jet cabinets followed by low-velocity air blow-off. Thin walls below 1.0 mm should be separated from support with reduced pressure or pre-softened; manual scraping can deflect the wall and leave a local stress concentration. If an alkaline support removal bath is used, residual hydroxide in blind holes must be rinsed completely because the alkaline film can haze the surface and attack the surface over time. After rinsing, parts should be dried at less than 40 °C; a hot air gun or drying oven overshoot above the heat deflection temperature can warp thin sections. Dimensional certification should be performed only after the part has returned to 23 °C and 50% RH for at least 24 h, per the conditioning reference of ASTM D618-21.

Feature resolution in RGD850 is controlled more by edge placement and support removal than by bulk cure shrinkage. Vertical walls built at 16 µm show less stair-stepping than those at 30 µm. Thin walls below 1.0 mm should be tied to a base gusset or reinforced rib because support removal introduces bending loads. Text and embossed logos must retain a minimum stroke width that is qualified on the target machine; a common production rule is 0.5 mm stroke width, but published data for this specific configuration is limited. Blind holes below 1.0 mm diameter can retain support material if not oriented for drainage. On perforated plates, hole centers should be staggered relative to jetting travel to avoid periodic missing-jet lines.

When FullCure850 Is Substituted for Machined ABS in Non-Transparent Fit Fixtures

FullCure850 is specified for assembly fixtures and form/fit gauges because the opaque grey surface provides contrast against light-colored components. The operative thermal boundary is the published heat deflection temperature of 45–50 °C at 0.45 MPa load per ASTM D648-18. In a wash booth, paint-bake cycle, or engine-bay fixture, the temperature should not exceed 40 °C under continuous load. Machined ABS fixtures often tolerate higher short-term heat; RGD850 does not duplicate that thermal profile and should not be substituted without a thermal soak test at the intended process temperature. At room temperature, the flexural modulus of 2200–3200 MPa is adequate for rigid gauging. However, the material exhibits lower impact toughness than many impact-modified ABS grades, so pressed-in steel inserts and clamp screws should be installed with controlled torque to avoid brittle cracking around holes.

Moisture uptake is moderate. The published water absorption range of 1.1–1.5% after 24 h immersion per ASTM D570-22 means that RGD850 is not a hydrolytically degrading material such as some condensation polymers, but repeated water-jet support removal and storage at high relative humidity can add surface moisture that shifts mass and feel. For applications requiring repeatable mass readings, parts should be dried and measured under controlled relative humidity. The material is not recommended for continuous immersion in water at elevated temperature, because the heat distortion boundary will be reached before meaningful chemical degradation is observed.

Post-cure is not required to initiate crosslinking because the jetted resin is exposed to in-situ UV lamps after deposition. If surface tack is observed after support removal, an optional UV flood exposure in the 320–390 nm UVA band may be used, but published data for residual monomer reduction in RGD850 under this specific post-cure is limited. Overexposure to broad-band UV can shift the grey pigment toward yellow and increase surface brittleness. When clear-coating is required for outdoor service or chemical protection, adhesion tests should follow ASTM D3359-23 on a flat RGD850 coupon because residual support film and low surface energy can reduce coating bond strength.

Why Opaque Grey Pigmentation Changes Scanning and Surface Inspection Workflows

Neutral grey surfaces returned by RGD850 are used in structured-light metrology because they reduce specular blow-out relative to white or translucent photopolymers. Blue-LED structured-light scanners and laser triangulation probes can resolve surface detail on the grey substrate without developer spray in many cases, but the part must be free of support residue and moisture. White-light scanners may still require a thin developer if the surface has been polished to a gloss. The material is not suitable for transmitted-light inspection or light-guide prototypes; VeroClear should be used where optical transmission is needed. The opacity of RGD850 also reduces internal feature visibility, which is an advantage for concealed fastener fixtures and a limitation for fluid-flow visualization models that require transparent channel walls.

When test reports are generated for RGD850 parts, the following test method designations are cited. The method number alone does not control print-path anisotropy; the specimen orientation and conditioning schedule must appear on the test report.

As a master pattern for room-temperature silicone tooling, RGD850 is acceptable when the surface is sealed and the silicone cure does not use aggressive amines. The grey surface provides a visible witness line for filleting and surface-defect correction. Dimensional change during a 24 h silicone cure at room temperature is generally below the noise of handheld measurement tools; for transfer of features below 0.5 mm, the master should be measured on a calibrated coordinate measuring machine before and after the silicone pour. Published data for this specific configuration is limited.

The standard RGD850 designation is not a regulatory certification; applications requiring food-contact or USP Class VI compliance must qualify the finished device under the applicable protocol rather than rely on material datasheet claims. Cleaning with ketone, chlorinated, or aromatic solvents should be avoided unless stress-cracking resistance is explicitly tested according to ASTM D543-20. Mild soap and water or a short aliphatic wipe is the accepted production cleaning route. RGD850 cartridges should remain sealed until loading and must not be frozen. Incompatibility with amine-containing sealants or uncured epoxy coatings should be considered when the grey part is used as a master pattern, because some amine curatives can attack the acrylate surface and transfer contamination to the silicone tool.