Resin Types

The main families

Resin names are not standardized across makers. "ABS-like" and "tough" are each maker's description of its own formulation, not a test grade, so compare the technical data sheets when you need a number. Formlabs also notes that which materials you can use depends heavily on the maker and printer.

Type	What makers describe it for	Trade-off to expect
Standard or general purpose	High-resolution models, figures, concept and looks-like prototypes (Formlabs, Anycubic)	Limited toughness compared with tough and ABS-like resins, which makers sell for impact and flexing (some list light snap-fits for their standard resin)
ABS-like	Functional parts that bend or rub repeatedly, such as buckles and jig parts (Anycubic)	Properties vary by product; check its data sheet
Tough	Parts that take compression, stretching, bending and impact; Formlabs likens its tough resins to HDPE, ABS or PP	Formulations differ widely between makers
Flexible and elastic	Rubber-, TPU- or silicone-like parts that survive repeated bending and compression (Formlabs)	Much softer parts; follow the maker's support and cure guidance
Water-washable	Cleaning with water instead of IPA (Anycubic)	Same skin hazards; long soaking can crack parts; wash water is hazardous waste
High temperature	Hot air, gas and fluid flow, heat-resistant mounts, molds and inserts (Formlabs)	A specialty material; check the heat rating on its data sheet
Castable	Investment casting patterns for metal and jewelry; Formlabs' Clear Cast is designed to burn out cleanly with low thermal expansion	Follow the maker's casting instructions
Engineering (rigid, ESD, flame retardant and similar)	Jigs, tooling, stiff load-bearing parts, anti-static parts, flame-retardant parts (Formlabs)	Availability depends on the maker and printer

Choosing one

1. Decide what the part must survive. Display piece or miniature: standard. Snap fits, clips, drops: ABS-like or tough. Squeeze or bend: flexible. Heat: high temperature. Metal casting: castable.
2. Check it is made for your printer. Use a resin with a published exposure profile for your machine, or plan to run the maker's exposure test; see Resin Exposure Settings.
3. Read the technical data sheet for the number that matters (elongation, impact, heat deflection). Marketing names alone do not tell you how two products compare.
4. Read the safety data sheet before you open the bottle. It sets the gloves, eye protection, ventilation and disposal for that resin.

Water-washable resin

Anycubic describes its water-wash resin as cleanable with water instead of IPA, and lists the trade-offs: water can damage models, prints should be dried before curing, and long soaking can cause cracks. It also states that the residual liquid is hazardous and must not go down the drain. eSUN's data sheet for its water-washable resin recommends curing material before disposal and states: do not empty into drains. Never pour resin wash water down a sink or drain; it carries dissolved liquid resin. Handle it as resin waste: see Resin Waste and Disposal and Washing and Curing Resin Prints.

The same caution applies to resins sold as plant-based or low-odor. Anycubic says its plant-based resin is not 100 percent safe and still advises gloves, masks and ventilation. Formlabs points out that toxicity cannot be judged by smell.

Skin, eyes and sensitization

Formlabs explains that what people call a resin allergy is sensitization: an immune response that builds with cumulative exposure and, once established, lasts. The reaction is not necessarily limited to the skin that touched the resin. Because it is cumulative, Formlabs says minimizing contact is the most effective prevention.

• Wear gloves whenever you handle liquid resin or unwashed parts, regardless of the resin, as Formlabs advises. Its Black Resin SDS calls for chemical-resistant, impervious gloves.
• Wear eye protection: safety glasses or goggles per the Formlabs SDS; eSUN recommends safety goggles with side shields.
• If resin gets on skin, wash it well with soap and water (Formlabs).
• If resin gets in your eyes, rinse cautiously with water for several minutes, removing contact lenses if easy, and get medical advice if irritation persists, as the Formlabs SDS directs.
• Cured parts are not automatically safe to handle. Formlabs notes that an incompletely cured part can still cause a reaction. Wash and post-cure as the resin maker says.

Ventilation

Ventilation needs depend on the resin. Formlabs says its own resins do not need dedicated ventilation, but also that some resin and printer combinations do, and that the SDS is where to check. The Formlabs Black Resin SDS says to use only with adequate ventilation, and eSUN lists respiratory irritation from its uncured resin. When the SDS asks for ventilation, provide it; see Resin PPE.

Storage and disposal

The Formlabs SDS says to store resin in a cool, dry, well-ventilated place out of direct sunlight and away from food and drink. It also says to prevent spills from reaching drains, sewers and waterways. Formlabs says never to pour resin down the sink, and that larger quantities should be cured solid or taken to a local drop-off site; rules vary by region. See Resin Waste and Disposal.