Full-Color Gypsum (Full-Color Sandstone)

Full-color gypsum, often sold as full-color sandstone, is printed by binder jetting on a gypsum-based (calcium sulfate) powder. A recoater spreads a thin powder layer, and inkjet print heads deposit a binder together with colored binders that dye the powder where the part forms, so the color is built into every layer instead of being painted on. The loose powder supports the part during printing; afterward the part is dried, depowdered and infiltrated to gain strength and full color depth.

Choose it for models whose value lies in color and form: architectural and urban models, terrain and GIS models, product concept models, anatomical teaching models and figurines. It is one of the most economical ways to get a multi-color model in one piece. The limits are clear: parts are brittle, sensitive to moisture and heat, and have a matte, slightly grainy surface, so they are display models, not functional parts. Full-color binder jetting is a specialized process: request it in the quote notes; feasibility, infiltration options and lead time are confirmed in quote review.

Mechanical and physical properties

Designing for full-color binder jetting

The powder bed supports every overhang, so no support structures are needed and parts can be nested in three dimensions. Strength and color quality, not supports, set the design rules:

• Walls and thin features: keep walls at about 2 mm or more and thicken slender features such as antennas, railings, limbs and trees, which can break during depowdering. Fillets at joints help.
• Hollowing: large solid models are heavy and consume a lot of powder. Hollow them with a wall of about 3 mm or more and add at least two openings of about 5 mm or more so that the loose powder can be removed.
• No closed cavities: enclosed volumes stay filled with loose powder, which adds weight and can leak out later.
• Moving and interlocking parts: avoid them. The material is too brittle for snap-fits, hinges or threads; print separate parts with clearance and assemble them afterward.
• Large models: build envelopes are a few hundred millimeters, so larger models are printed in sections with alignment features and bonded after printing.
• Scale: models are often reduced from real-world size, so check that walls and details still meet the minimums at the printed scale.

Color files and color accuracy

Color comes from the model file, so it has to travel with the geometry. 3MF is the preferred format when color matters; STL carries no color. If your color data exists as OBJ with texture images or as PLY with vertex colors, attach it as a ZIP file and mention it in the request so that it can be checked in review. Printed colors are matte and usually slightly less saturated than on screen, very fine lines can blur a little because the binder spreads into the powder, and colors can vary slightly between builds. Provide a reference image for critical colors, and have the part painted when an exact color match is required.

Tolerances and surface

Accuracy depends on part size, orientation, powder shrinkage and infiltration. Plan for deviations of a few tenths of a millimeter on typical model sizes and more on large or thin parts; final values are confirmed in the quote and order review. Precise fits are not the strength of this material, so leave generous clearance where sections are assembled. The surface is matte and slightly grainy; infiltration deepens the color, but only a clear coat makes the surface glossy.

Infiltration and finishing options

Freshly printed parts are fragile and look pale. Infiltration soaks a liquid resin or wax into the porous part, which raises strength and brings out the full color. The infiltrant is chosen with the supplier:

Cost and lead-time drivers

Full-color binder jetting is one of the lower-cost ways to produce color models, because no support material is needed and many parts share one build. The main levers:

• Part volume: powder and binder consumption follow the solid volume, so hollowing large models reduces cost noticeably.
• Build height and nesting: parts can be stacked in the powder bed, and several models in one build share the machine time.
• Infiltration and handling: depowdering and infiltration are manual steps, and large or delicate models take more time.
• Sectioning and assembly: models larger than the build envelope need bonding and touch-up work.
• Packaging and lead time: fragile models need protective packaging; feasibility, infiltration and lead time are confirmed in quote review.

Full-color gypsum vs. other color options

Choose full-color gypsum when many colors, textures or gradients must be printed in one piece at moderate cost and the model will mostly be looked at. PolyJet full color costs more but gives sharper color and tougher parts that survive handling. Painted SLA is the better route when a few exact colors matter more than gradients, and dyed or painted nylon when the part must also be durable.

When not to choose full-color gypsum

Typical applications

• Architectural, interior and urban planning models with colored facades and landscaping.
• Terrain, geological and GIS models with elevation and data coloring.
• Product concept and packaging models for design reviews.
• Anatomical models for teaching and communication.
• Figurines, characters, game pieces and collectibles.
• Visualizations of simulation results, such as stress or flow color maps.

Specifying full-color gypsum on Uretyco

1. 1
   Prepare the color model

   Export a 3MF file with color data, check scale and units, and make sure walls and details meet the minimums at the printed size.

2. 2
   Upload and request full-color binder jetting

   Name full-color gypsum in the quote notes, or describe the model so the assistant can suggest it. Attach OBJ or PLY color data as a ZIP file if no 3MF is available.

3. 3
   Choose infiltration and finish

   State whether the model will stand on a desk, be exhibited or be handled often, so that the infiltrant and any clear coat can be chosen accordingly.

4. 4
   Describe your color expectations

   Add a reference image for critical colors and logos, and note where an exact match would require painting instead.

5. 5
   Review the quote

   Feasibility, sectioning of large models, packaging and lead time are confirmed in quote review before production starts.

FAQ

Is full-color sandstone real sandstone?

No. It is a gypsum-based composite, mainly calcium sulfate, that is bound and colored in the printer and then infiltrated. The name comes from its matte, stone-like look and feel.

How accurate are the colors?

Good enough for most presentation models, but not an exact match. Printed colors are matte, usually a little less saturated than on screen, and can vary slightly between builds. For brand colors or RAL shades, a painted part is the reliable route; PolyJet full color comes closer than gypsum but is not exact either.

Can full-color gypsum parts be used as functional parts?

No. They are brittle, weak in bending and sensitive to moisture and heat. Use them to show form and color; for parts that must carry load, snap together or be handled often, choose nylon (MJF or SLS), SLA or PolyJet materials.

Full-color gypsum or PolyJet full color?

Gypsum costs less and suits larger, static models such as buildings and terrain. PolyJet offers smoother surfaces, sharper and more saturated color, optional transparent areas and parts that survive handling, at a higher price.

Related resources

• PolyJet Rigid OpaqueSmooth, multi-color photopolymer models.
• Standard SLA ResinSmooth models for painting.
• PA12 (Nylon 12)Durable printed parts that can be dyed.
• 3D PrintingTechnologies, files and cost drivers.
• Supported File Formats3MF and other files for color printing.
• Shipping, Packaging & DeliveryHow parts are packed and shipped.