Resin Types Explained: Standard, Tough, Flexible, Castable & More

Resin Types at a Glance

Unlike FDM filament where PLA/PETG cover most needs, resin printing has specialised formulations for specific applications. Using the wrong resin type leads to failed prints or parts that don't perform their intended function.

Standard Resin

What it is: The default. General-purpose photopolymer resin designed for detail and ease of use.

Best for: Display models, miniatures, figurines, prototypes where detail matters more than strength.

Pros: High detail, smooth surface finish, affordable, widely available.

Cons: Brittle, not suitable for functional parts, UV-sensitive (yellows over time).

Exposure: Bottom 30-50s, normal 2-3s (varies by printer).

Tough / Durable Resin

What it is: Formulations that resist breaking and can handle stress without shattering.

Best for: Functional prototypes, parts that need to withstand impact or stress, snap-fit components.

Pros: Impact-resistant, better layer adhesion, can be machined or drilled.

Cons: More expensive, longer cure times, may yellow faster.

Exposure: Bottom 40-60s, normal 3-5s.

Flexible Resin

What it is: Rubber-like material that bends and compresses. Shore hardness varies by brand (typically 50-80A).

Best for: Gaskets, grips, flexible hinges, wearable parts, stamps.

Pros: Genuine flexibility, can bend repeatedly without breaking.

Cons: Difficult to print — needs higher exposure, longer peel times. Support removal harder.

Exposure: Bottom 50-70s, normal 4-6s.

Water-Washable Resin

What it is: Standard resin modified to clean with water instead of IPA.

Best for: Hobbyists without good IPA access, people wanting simpler post-processing.

Pros: No IPA needed for cleaning, less odour, easier disposal.

Cons: Not actually better — just different cleanup. Can be more brittle than standard resin. Water disposal still requires curing.

Exposure: Bottom 35-50s, normal 2.5-4s.

Castable Resin

What it is: Resin designed to burn out cleanly in investment casting. Used for jewellery and dental applications.

Best for: Jewellery making, dental frameworks, metal casting patterns.

Pros: Burns clean with minimal ash, high detail retention.

Cons: Expensive, requires proper burnout schedule, specialised use case.

Exposure: Bottom 40-60s, normal 3-5s (check manufacturer recommendations).

Dental Resin

What it is: Biocompatible resins for dental applications — models, aligners, surgical guides.

Best for: Dental professionals, orthodontic models, surgical planning.

Pros: Dimensionally stable, some biocompatible grades available.

Cons: Very expensive, strict handling requirements, certification needed for medical use.

High-Temperature Resin

What it is: Resins that maintain properties at elevated temperatures (up to 200-300°C).

Best for: Moulds for low-temp casting, parts exposed to heat.

Pros: Won't deform at temperatures that melt standard resin.

Cons: Expensive, brittle, longer post-cure requirements.

Clear / Transparent Resin

What it is: Formulated to be optically clear after proper post-processing.

Best for: Lenses, light pipes, transparent prototypes, fluidic devices.

Pros: Can achieve glass-like clarity with proper finishing.

Cons: Requires careful post-processing (sanding, polishing, proper curing). Yellowing common over time.

Quick Selector

Resin Handling Essentials

All resins require:

• Nitrile gloves when handling
• Ventilated workspace
• Protection from UV light (store in opaque containers)
• Shaking/stirring before use
• Proper disposal (cure before bin, never drain)

Resin shelf life: Most resins last 12-24 months when stored properly (cool, dark, sealed). Expired resin may not cure properly.

Price Guide

Starting Point

For most people: buy a litre of standard resin. Learn to print with it. Then branch into tough or flexible resins when you have a specific need. The other types are worth knowing about but not necessary until you have a specific project that requires them.