Technical Bulletin - Printing settings vs Curing Rate Control (CRT)
Many photopolymer suppliers provide fixed printing settings per printer model to simplify user onboarding. While this approach appears practical, it introduces fundamental limitations when evaluated from an engineering and process control perspective.
This bulletin analyzes the advantages and limitations of fixed parameter strategies compared to the 3Dresyns® Curing Rate Control (CRT) system, a calibration-based methodology designed to deliver reproducible performance across printers, materials and workflows.
1. Fixed printing settings — perceived advantages
Providing predefined printing settings per printer model offers an apparent simplification of the user experience.
| Advantage | Description |
| Ease of use | Users can start printing immediately without calibration or process understanding. |
| Reduced entry barrier | Suitable for beginners or non-engineering environments. |
| Fast onboarding | Initial prints can be obtained quickly using predefined exposure parameters. |
These advantages are primarily related to short-term usability, not long-term process control or reproducibility.
2. Fundamental limitations of fixed settings
From a materials science and process engineering perspective, fixed settings are inherently non-robust.
| Limitation | Technical implication |
| Printer-to-printer variability | Even identical printer models exhibit significant variation in light power due to manufacturing tolerances. |
| Non-uniform light distribution | LCD and DLP systems deliver higher irradiance at the center and lower at edges and corners, leading to spatial variability in curing. |
| Aging of optical systems | LCD panels and DLP projectors lose intensity over time, shifting curing kinetics and invalidating predefined settings. |
| Dependency on Z-layer definition | Supplier settings are typically optimized for a single layer thickness, limiting flexibility. |
| Restricted process window | Users cannot reliably adjust layer thickness, exposure strategy or printing speed without revalidation. |
| Lack of material-process decoupling | Settings do not separate resin kinetics from machine conditions, preventing true engineering control. |
As a result, fixed settings often lead to inconsistent results, poor reproducibility and limited scalability in industrial environments.
3. CRT — calibration-based engineering control
The 3Dresyns® Curing Rate Control (CRT) system replaces fixed settings with a calibration-based methodology that directly links exposure energy to cured thickness.
Instead of assuming constant printer behavior, CRT characterizes the actual curing kinetics of each resin on each specific printer under real operating conditions.
- Calibration typically requires a minimum of three exposure points
- Total calibration time is typically under 10 minutes
- Results define a material–printer “curing fingerprint”
This approach captures the real interaction between:
- Resin chemistry
- Printer light power and distribution
- Optical system condition (new vs aged)
- Selected process parameters
4. CRT vs fixed settings — engineering comparison
| Aspect | Fixed settings | CRT system |
| Initial setup | Immediate | Requires short calibration |
| Printer variability | Not compensated | Fully captured |
| Light aging effects | Ignored | Integrated in calibration |
| Layer thickness flexibility | Limited | Fully adjustable |
| Reproducibility | Low to moderate | High |
| Process control | Empirical | Engineering-based |
5. Enabling process flexibility
One of the main limitations of fixed settings is the restriction to a predefined layer thickness.
CRT enables users to:
- Select any layer thickness (Z resolution)
- Adjust exposure based on required cured depth
- Optimize between speed and accuracy
- Maintain dimensional consistency across builds
This is particularly relevant in advanced applications where geometry, resolution and throughput must be balanced.
6. Integration with Fine Tuners
CRT can be combined with 3Dresyns® Fine Tuning additives to further control material behavior.
- Increase dimensional accuracy
- Reduce overcuring and light bleed
- Adjust curing speed
- Improve feature definition
This creates a multi-variable control system where both process parameters and material response can be engineered.
7. Conclusion
Predefined printer settings may appear convenient, but they are fundamentally unreliable in photopolymer additive manufacturing. Even when the printer model is nominally identical, real curing conditions vary due to differences in light output between units, non-uniform irradiance across the build area, progressive optical aging, and the fact that most fixed parameters are defined around a single assumed layer thickness.
As a result, fixed printing settings may provide short-term ease of use, but they are not compatible with controlled, reproducible additive manufacturing. Variations in light power, spatial distribution, machine condition and process context make predefined parameters inherently unstable.
The CRT system addresses these limitations through a calibration-based framework that captures the real curing behavior of each resin on each specific printer under its actual operating condition. This enables printer-independent reproducibility, full control over layer thickness, adaptation to real machine conditions, and integration with advanced material tuning.
In this context, the transition from fixed settings to CRT represents a shift from trial-and-error printing toward engineered additive manufacturing systems.