Stereolithography Resin
TriMech can 3D print accurate, complex investment casting patterns with excellent surface finish.
Somos® WaterShed AF is a multi-purpose stereolithography resin that meets the requirements for investment casting patterns as it has been designed without antimony to address sensitivities in the casting of certain specialty alloys.
As no antimony is used, patterns created with Somos® WaterShed AF leave much lower amounts of ash residue after burnout, reducing clean-up and speeding up mold production.

Somos WaterShed AF Material Profile
Learn more about the Stratasys Stereolithography 3D printing technology used to make parts
Stratasys Neo Stereolithography 3D Printer
With the Neo Stereolithography 3D printer we can create smooth-surfaced prototypes, master patterns, large concept models and investment casting patterns more quickly and more precisely than ever before.

Main Uses
Investment casting patterns, the resin is designed without antimony to address sensitivities in the casting of certain specialty alloys.
Material Features and Applications
No detectable levels of antimony per ICP-AES test methodology
Trace amounts of ash that are easily removed
Low viscosity
Dimensionally stable
Suitable for high-end alloy castings
Rapid draining
Produces accurate, repeatable parts regardless of size
Somos Material Specification
Properties and testing results for the Somos 3D printing resin materials
Material Name | Description | Tensile Strength (ASTM D638M) | Elongation at Break (ASTM D638M) | Tensile Modulus (ASTM D638M) | HDT @ 0.46 MPa (ASTM D648) | Notched Izod Impact (ASTM D256A) | Color |
---|---|---|---|---|---|---|---|
Somos® WaterShed XC 11122 | Versatile, good all-round polymer, very easy to use | 50.4 MPa (at break) | 15.5% | 2,770 MPa | 50 °C | 25 J/m | Clear |
Somos® WaterClear Ultra 10122 | Versatile, easy to use, exceptional clarity | 56 MPa (at break) | 7.5% | 2,880 MPa | 47 °C | 25 J/m | Clear |
Somos® WaterShed Black | Versatile, good all-round polymer, very easy to use | 50.4 MPa (at break) | 15.5% | 2,770 MPa | 50 °C | 25 J/m | Black |
Somos® PerFORM | Very high heat and stiffness, ceramic | 68 MPa | 1.1% | 10,500 MPa | 269 °C | 17 J/m | White |
Somos® PerFORM Reflect | Very high heat and stiffness, ceramic, developed for PIV | 63.3 MPa | 0.8% | 10,135 MPa | 276 °C | 17 J/m | Orange |
Somos® Taurus | High heat and toughness, thermoplastic like performance | 46.9 MPa (at yield) | 24% | 2,310 MPa | 62-91 °C | 47.5 J/m | Charcoal |
Somos® EvoLVe 128 | Very tough and durable with great surface finish | 56.8 MPa (at yield) | 11% | 2,694 MPa | 52 °C | 39 J/m | White |
Somos® WaterShed AF | Print accurate, complex investment casting patterns with excellent surface finish | 46 MPa | 10% | 2,460 MPa | 50 °C | 34 J/m | Clear |
Somos® 9120 | Versatile, good all round polymer, very easy to use | 31 MPa | 20% | 1,350 MPa | n/a | 51 J/m | Clear |
Somos® BioClear | For non-implantable limited body contact (<24hr) medical and dental applications | 50.4 MPa (at break) | 15.5% | 2,770 MPa | 50 °C | 25 J/m | Clear |
Somos® DMX SL-100 | Durable and tough for production of complex, hollow composite parts | 29.7–32.1 MPa (at break) | 12–28% | 2,260–2,560 MPa | 44 °C | 0.61–0.71 J/m | Off white |
Stereolithography (SLA) Technology
Advantages of parts built with a Stratasys Stereolithography Machine
What is Stereolithography?
Stereolithography (SL/SLA) was the world’s first 3D printing technology, and it remains a great option for highly detailed prototypes that require tight tolerances and smooth surfaces. It uses a UV laser to cure and solidify fine layers of photopolymer in an open vat.
Why choose SLA?
SLA is great for prototyping parts that will ultimately be painted or coated because the models can be finished using the same materials and processes as the end product. Transparent, heat resistant and moisture resistant materials are also attractive for medical, automotive and other prototypes that call for flow visualization, light transmittance or thermostability.
SLA benefits
Product designers opt for SL models when a quick build time is crucial, and they can invest time and resources into additional finishing processes. SL can also produce master patterns for urethane casting, and investment casting patterns that are used to produce metal parts for aerospace, automotive, power generation and medical applications.