Instructions for Use (IFU) & Printing Parameters for DLP & LCD printers

These Instructions for Use (IFU) and Printing Parameters define the governing workflow, qualified starting parameter windows, calibration logic and user responsibilities for 3Dresyns® photopolymer resin systems processed by DLP, LCD and MSLA vat photopolymerization technologies.

3Dresyns® materials are multivariable photopolymer systems. Final part properties are not intrinsic constants of the liquid resin alone, but depend on the complete material–printer–process–post-processing chain, including printer optics, real light power, exposure strategy, printing temperature, resin homogeneity, washing chemistry, drying conditions, post-curing wavelength, post-curing power, post-curing time and any validated fine tuning.

Final performance, safety and application suitability depend on strict adherence to qualified workflows. Deviation from these instructions may significantly affect mechanical behaviour, surface quality, dimensional fidelity, functional performance and long-term stability.

1) Scope, limitations and responsibilities

Scope of application

This document applies to 3Dresyns® photopolymer resin systems processed by vat photopolymerization technologies using DLP, LCD and MSLA exposure systems.

These instructions define general processing methodology and qualified starting workflows. They do not replace:

• printer-specific IFU supplements,
• application-specific validation required by the user,
• regulatory qualification required by the legal manufacturer or user,
• material-specific TDS, CRT packages or application-specific IFUs where applicable.

Limitations

This document provides qualified starting parameter windows and validated calibration methodology. It does not replace user-side verification. Users remain responsible for confirming suitability for their printer, geometry, workflow and intended application.

2) Material system and version control

3Dresyns® photopolymer resins are supplied as system-based materials that may exist in multiple formulation versions, viscosities, colours and functional configurations.

Before printing, verify that the selected resin version, lot number and associated documentation correspond to the intended printer technology and application.

Mixing versions, changing formulations or transferring parameters between materially different systems may invalidate expected performance.

Resin homogenization before printing

Resin homogeneity is part of process control. Materials should be mixed or homogenised appropriately before printing and re-homogenised as needed after storage, especially where pigments, fillers or functional additives may settle over time.

3) Printer compatibility and exposure architecture

Vat photopolymerization includes different optical architectures that require technology-specific workflows.

• DLP, LCD and MSLA systems expose complete layers simultaneously.

Exposure strategy, support logic and calibration settings must not be transferred between different printer models, optical engines or exposure configurations without re-evaluation.

4) Real light power, printer variability and drift

Generic exposure times are only approximate because the exposure time required to cure a given resin depends strongly on the real light power available at the vat, not only on the nominal printer specification.

• Different printers of the same type may show different real light power.
• Even different units of the same model may differ in effective power.
• Light power decays over cumulative operating time or working hours.
• Lower real power requires longer exposure times. Higher real power permits shorter exposure times.

For this reason, printer-independent fixed exposure times must not be interpreted as universal settings. Exposure must be selected through measured or validated calibration logic.

Recommended control approach

• When possible, measure real light power with a suitable radiometer.
• Evaluate the centre, sides and corners of the printable area.
• Re-check the printer periodically to account for light-power decay over time.
• Recalibrate exposure after major maintenance, optical changes, screen replacement or significant cumulative use.

5) Standard starting printing parameters (qualified quick baseline)

These values are practical starting points and must be validated for each resin system, printer and application.

Interpretation rule: these values are not universal recipes. They are intended as a quick baseline from which the user performs structured CRT-based optimisation on the target machine.

Why these are only starting values

• Real light power varies across the vat.
• Real light power decays over cumulative printer use.
• Different resin systems require different curing energies.
• Target layer thickness directly affects the required cured depth.
• Geometry, supports, temperature and post-processing all influence the final result.

Record keeping (minimum)

For traceability and reproducibility, record at minimum:

• resin name, version, colour, additives and lot number,
• printer model, exposure architecture and wavelength,
• real measured light power if available,
• layer height and exposure settings,
• orientation and support strategy,
• washing chemistry, time and temperature,
• drying method and time,
• post-curing wavelength, power and time,
• ambient temperature and any controlled thermal steps.

6) Why CRT is more flexible than fixed parameter presets

A major advantage of CRT-based calibration is that it allows the user to re-optimise printing settings for different Z layer thicknesses depending on whether the goal is higher speed, higher XY/Z resolution, improved dimensional control or a different balance between these variables.

With CRT, exposure selection is linked to measured curing behaviour. This means the user can move from one target layer thickness to another and re-select the corresponding exposure window in a structured way.

By contrast, many workflows in the market are organised around fixed print settings tied to specific materials and specific layer heights. In those cases, changing the layer thickness often requires switching to another preset or manually creating and tuning a new print setting. CRT offers a broader engineering framework for adapting the same resin system to different Z strategies on the target printer.

• Need faster printing? Increase layer thickness and recalibrate exposure with CRT.
• Need finer Z resolution? Reduce layer thickness and recalibrate exposure with CRT.
• Need different trade-offs for different parts? Use the same resin with different validated CRT-derived settings.

This is one of the main advantages of CRT compared with workflows based on fixed parameter presets tied to isolated Z-layer configurations.

7) Fast CRT logic for rapid exposure selection

The Curing Rate Table (CRT) is the most practical method for selecting exposure times based on the real curing behaviour of the resin in the specific printer.

A full CRT may include many exposure points. However, for routine implementation a fast CRT can often be established quickly by starting with only three points: 5 s, 10 s and 15 s.

In many practical cases, 2–4 bottom layers at 75–100 s provide a useful initial adhesion baseline, but this must still be validated for the specific resin-printer system. The main optimisation task then becomes the selection of the correct standard-layer exposure window.

How to extend the fast CRT

• If the target exposure is likely in the fast interval, add 1–2 measurements between 1 and 5 s or between 5 and 10 s.
• If the resin is slower, more filled, darker or the printer has relatively low light power, add 1–2 measurements between 15 and 20 s.
• If needed, continue with longer times for slow-curing systems.

This gives a fast, structured and economical way to identify a starting exposure without building a full long CRT from the beginning.

8) Curing Rate Table (CRT) methodology

CRT concept

The Curing Rate Table (CRT) is a resin–printer fingerprint. It establishes the relationship between exposure time and cured thickness under defined optical conditions.

CRT values shown in examples are illustrative only and must not be interpreted as universal settings.

How CRT is measured

• Remove the build platform from the printer.
• Place a small drop of liquid resin on a clean microscope glass slide.
• Position the slide in the printer, typically near the centre of the vat area for the exposure test.
• Expose for a selected time.
• Remove uncured resin gently.
• Measure cured thickness with a calliper or micrometre.
• Record thickness and green-state quality.
• Repeat for the next exposure time.

Recommended CRT time series

For broader screening, the classical sequence may include 2, 5, 10, 15, 20, 25, 30, 50, 75 and 100 s. For rapid implementation, the recommended fast start is 5, 10 and 15 s, followed by one or two additional points in the most relevant interval.

How to select standard-layer exposure

As a general rule, select a standard exposure that cures approximately the target layer thickness multiplied by an appropriate cure-thickness factor. The correct factor depends on the combined behaviour of the material system, including its curing kinetics, green-state mechanical resistance, physical behaviour during separation and adhesion characteristics.

Important note: these factors are approximate, not fixed rules. Different resins may show different kinetic, mechanical, physical and adhesive behaviour, and therefore may require different exposure margins even at the same nominal layer thickness.

Why this distinction matters:

• Fast and brittle resins may become over-cured too easily. Excessive exposure can increase brittleness, increase adhesion to the FEP or release film, reduce fine detail and raise the risk of crack initiation or part breakage during separation.
• Softer, less brittle or slower-curing resins tend to tolerate a higher initial cure-thickness factor. In these systems, the more common initial risk is insufficient green strength, leading to deformation, tearing or part failure due to under-curing during peeling.

This logic is consistent with the historical 3Dresyns calibration methodology: the first trial often starts close to 1.5 cured layers, then moves lower when printing is already successful and higher when the selected exposure remains too weak for reliable printing.

• If the resin prints well and the goal is more speed and finer detail, move towards 1.1–1.2×.
• If the part remains too soft, too weak or too peel-sensitive, move towards 1.3–1.5× or, when necessary, even higher until reliable green strength is achieved.

Examples:

• For a target layer of 50 µm, a brittle fast resin may start near 50–60 µm cured thickness, while a slower or softer resin may start near 65–75 µm.
• For a target layer of 100 µm, a brittle fast resin may start near 100–120 µm, while a slower or softer resin may start near 130–150 µm.

How to select bottom-layer exposure

For initial platform adhesion, a practical baseline is typically 2–4 bottom layers at 75–100 s. In many practical cases, this is already sufficient for initial adhesion, so the main unknown becomes the correct standard-layer exposure, which can then be refined using a fast CRT. This baseline must still be validated for the specific resin-printer system.

Where a CRT has been measured, a more structured method is to use a long exposure at which the resin shows strong curing and strong adhesion in the drop test.

9) Practical interpretation of cure behaviour

• Under-cured: soft, weak, tender or easily deformable material; insufficient green strength; higher risk of tearing or breaking during peeling; increase exposure.
• Well cured: sufficient green strength, controlled adhesion, stable printing behaviour and acceptable detail retention.
• Over-cured: excessive adhesion to the FEP or build surface, loss of detail, increased brittleness, excessive stress during separation and higher risk of crack initiation or part fracture; reduce exposure.

Application rule:

• If the resin is fast and fragile, avoid unnecessarily high exposure. These systems often perform better closer to 1.0–1.2× the target layer thickness.
• If the resin is slower, softer or less fragile, avoid under-curing. These systems often require a safer initial window closer to 1.3–1.5×.

The goal is not maximum cure. The goal is the minimum exposure that still gives enough green strength for reliable separation, stable printing and acceptable dimensional fidelity.

10) Initial validation with 3Dresyns calibration files

Once initial exposure settings have been selected, validate them using the 3Dresyns calibration files.

• Download 3Dtest1 calibration STL file
• Download 3Dtest2 calibration STL file

10.1 3Dtest1 — flat coin without supports

This first fast calibration test is intended to verify:

• general printability,
• adhesion logic,
• XY resolution,
• appropriateness of the standard-layer exposure.

The flat coin is a low-consumption validation geometry. The smallest concentric feature clearly reproduced gives an indication of the achievable XY resolution under the chosen settings.

The test geometry includes concentric features from larger lines down to very fine dimensions. The thinnest clearly resolved feature gives a practical indication of the XY limit under those settings.

• The first concentric line starts at 500 µm (0.5 mm).
• The following lines include 400, 300, 200, 150, 100, 80, 60, 40, 20, 10, 5 and 2 µm nominal widths and depths.

10.2 3Dtest2 — flat coin with supports

Once 3Dtest1 prints correctly, 3Dtest2 is used to evaluate:

• support behaviour,
• XYZ printability,
• Z accuracy,
• surface marking associated with support contact.

The printed thickness can be compared with the theoretical thickness to estimate Z-axis relative error.

Example:

• nominal thickness: 2.0 mm
• measured thickness: 2.1 mm
• relative Z error: 5%

The support tips are intentionally thin to help evaluate the use of minimum or near-minimum support contact size and the corresponding effect on surface marking.

11) Structured troubleshooting logic

Failure mode 1 — complete detachment from build platform

If the printed part detaches completely from the build platform, increase:

• bottom-layer exposure time, and/or
• number of bottom layers.

Failure mode 2 — printed part remains too tender

If the printed geometry is too soft, weak or tender, the standard-layer exposure is too low. Increase exposure.

Failure mode 3 — printed part remains too brittle or heavily over-adhered

If the printed geometry is too brittle, excessively adhered or loses detail, the standard-layer exposure may be too high. Reduce exposure.

Failure mode 4 — insufficient XY detail

If printability is acceptable but the smallest features are poorly resolved, reduce overcuring by lowering exposure, reducing light power where possible, or applying validated fine tuning.

12) Temperature control and viscous resins

Temperature control is often helpful for viscous systems. Maintaining a controlled and constant printing temperature may improve flow, recoating consistency and reproducibility.

As a practical starting point, viscous resins may be warmed to approximately 30–35 °C, but this must be validated because temperature changes also affect viscosity, curing behaviour and process stability.

13) Optional advanced screening geometry

For large parts or comparative material screening, a wedge geometry may optionally be used to assess separation force, relative rigidity or flexibility threshold and comparative fracture behaviour. This is an advanced screening tool and should not replace 3Dtest1 and 3Dtest2 for routine implementation.

14) Optional fine tuning

Once the baseline workflow is stable, 3Dresyns® resins may be fine tuned to adjust printing speed, detail, dimensional accuracy or process robustness. Fine tuning must be carried out in a structured, traceable manner.

15) Cleaning, drying and post-curing

Post-processing is a critical part of the process. Final physical and mechanical performance depends strongly on:

• cleaning chemistry,
• cleaning time and temperature,
• drying method and completeness,
• post-curing wavelength,
• post-curing power,
• post-curing time,
• post-curing temperature where relevant.

Printed parts must undergo the qualified cleaning, drying and post-curing workflow defined for the selected resin family and application. Deviation from qualified post-processing may significantly alter surface chemistry, dimensional stability, mechanical performance and long-term behaviour.

Drying before post-curing is mandatory. Washed parts must be fully dried before final UV or thermal post-curing. Residual solvent or cleaning fluid may compromise surface quality, curing consistency, final mechanical properties and equipment cleanliness.

Post-curing settings are formulation-dependent. Time and temperature should remain linked to the correct material family and formulation version. Thick or bulky geometries may require more time to reach the intended curing temperature, while thin or poorly supported geometries may require greater care to avoid distortion or warpage during post-curing.

For specific material families, follow the dedicated related IFUs where applicable.

16) Handling, storage and contamination control

Resins and printed parts must be handled using appropriate protective equipment and contamination-control measures.

Materials should be stored under controlled conditions of temperature, light exposure and humidity. Cross-contamination between resin systems must be avoided.

Stored resin should be re-homogenised as needed before reuse, particularly after prolonged standing or where phase settling may have occurred.

17) Responsibilities of the user

Users are responsible for selecting appropriate materials, printers and workflows for their intended application.

Application-specific validation, regulatory compliance and final product qualification remain the responsibility of the user or legal manufacturer.

3Dresyns® does not assume responsibility for misuse, off-label application or deviation from qualified workflows.

18) Governing principle

3Dresyns® vat photopolymerization materials are system-dependent materials. Reported performance reflects typical outcomes obtained under qualified workflows and is not an intrinsic property of the liquid resin alone.

The most important practical rule is this: start from the qualified baseline in Section 5, establish a fast CRT with 5 s, 10 s and 15 s, add one or two extra points in the most relevant interval for the target layer thickness, use 2–4 bottom layers at 75–100 s as the initial adhesion baseline, and then validate with 3Dtest1 and 3Dtest2.

19) Related documentation

• Curing Rate Control System (CRT)
• Structured Calibration & Dimensional Control
• Power differences of DLP, LCD and MLCD printers and their consequences
• Unlocking the black box of resin 3D printing
• Resources

20) Need technical support?

For printer qualification, CRT definition, structured calibration or advanced optimisation, contact info@3dresyns.com.