Most grading problems surface too late: in samples, in production, in returns.
We catch them before you cut fabric.
The brands with the highest fit-related returns rarely have a factory problem or a grader problem. They have a grading visibility problem, one that doesn't show up until samples arrive or customers complain.
Nabla Labs runs a physics-based virtual fit check on every size in your range, across avatars shaped like your actual target customer's body, not just one fit model, and sends back a clear report and corrected patterns, before production starts.
Problem
Sizing problems that
are hard to see on paper.
Inconsistent fit between styles erodes customer trust and drives repeat returns, even when your specs look identical on paper.
Edge sizes are where grading breaks most often and where customers notice it most, but they're rarely stress-tested with the same rigour as the base.
Without a documented fit standard, every new factory or grader reinterprets your sizing from scratch, and the results vary.
One fit model on one size is not a fit validation. It's a best guess, and the rest of the run is untested until samples arrive or customers complain.
Differentiation
What downstream tools can't see,
and where the problem actually lives.
Size recommendation tools, virtual try-on widgets, and fit advisors all operate at the same point in the process: after the garment is designed, graded, and produced. What none of them can do is change the pattern. The fit problem they're managing was created months earlier, inside your grade rules. That's where Nabla Labs works.
Virtual Try‑On Lives Here
VTO works around existing fit problems by nudging shoppers towards the "least bad" size. It provides decision optimization: "Which size should I buy?"
Our Engine Lives Here
We simulate your DXF/CAD patterns on diverse avatars, detect where grading breaks, and resolve inconsistent fit before production starts.
Already using CLO 3D or Browzwear? Nabla Labs complements them.
Those tools show you how a garment looks, you still need someone to interpret what the simulation means across your size run and correct the grading. That's what we do.
Capability
What we deliver.
Ingest
Ingests your existing graded patterns (DXF/CAD and ASTM formats).
Analyse
Runs a virtual fit analysis on multiple body shapes across all sizes in the range.
Identify
Identifies tight, loose and unstable areas on each size with clear visual diagnostics.
Report
Produces a structured report you can use with your pattern maker, fit model and factory.
Visualize
Interactive web-based visualizations of simulations with various avatars, easy to watch and interact with, requiring no specialized hardware.
Optimize
Unlike diagnostic-only tools, Nabla Labs uses a closed-loop simulation engine, one that can compute what the corrected pattern geometry should look like, not just where the current grading fails. Optionally, you receive an adjusted DXF alongside the diagnostic report: a concrete proposed correction your pattern maker can review, refine, and approve. The fix is already in the file.
Beyond Traditional Grading
Classic grading services rely on rules and experience. However, they rarely observe how those rules behave on diverse bodies across the full size range.
We plug into the same DXF/CAD workflow, but stress‑test your grading virtually on diverse avatars. This allows us to highlight weak sizes and propose concrete, physics-based corrections before production.
Visual diagnostic feedback, highlighting fit improvements across all body shapes and sizes.
Scale
Fit model feedback, at scale.
A single fit session on one size tells you how one garment fits one body. It tells you almost nothing about how your grading behaves across the rest of the run, which is where the problems that reach customers are hiding.
Instead of relying on a single fit model and one or two sample sizes, you can run a virtual fit session across your full graded range and a variety of body shapes. You see where garments are likely to pull, collapse or lose balance, with the same kind of feedback you would get in a well‑run fit meeting, only more systematic, objective and repeatable.
Test multiple sizes and body types without sewing extra samples.
See how grading behaves on smaller, larger and different proportion bodies.
Stress-test garment fit in custom poses to validate comfort and functional ease where it matters most.
Get objective indicators (strain, ease, balance) to complement fit model comments.
Use virtual results to focus physical fit sessions on the most critical sizes.
Get automated fit recommendations by our physics engine, either as pattern adjustment descriptions or as an optimized, graded DXF/CAD file.
Visualizing contact points across the full size range allows for systematic detection of grading anomalies and volume distribution issues.
Outcomes
Results you can measure.
After a Nabla Labs analysis, your pattern maker has concrete notes on where to adjust, not just a feeling that something is off. Your fit sessions focus on the two or three sizes that actually need physical review, not a blind check of the full run. Your operations team has a documented fit standard that travels across factories and seasons. And you go into production knowing your edge sizes behave the way your base size does.
Fewer grading‑related sample rounds per style.
Reduced risk of fit issues appearing only in production or at retail.
Better use of fit model time, focused on sizes and areas flagged as high risk.
Clear, consistent size charts that reflect the garments you actually ship.
A documented grading standard that can be applied across suppliers.
Fit Risk Summary
| Size | Strain | Balance | Risk |
|---|---|---|---|
| XS | Low | Optimal | ● |
| M (Base) | Low | Optimal | ● |
| XXL | High | Unstable | ● |
| Plus 2X | Med | Loose | ● |
Integration
Designed to work with your current team.
Works with patterns from your existing grader, freelancer or factory.
Produces factory‑ready pattern files plus an additional fit report.
Gives technical designers and pattern makers concrete data on where grading breaks.
Helps fit models and fit technicians focus on problem sizes and problem zones instead of checking everything blindly.
Provides founders and product teams a clear view of sizing risk by style.
Grading Risk Overview
The "Legacy" Integration
Enterprise fit platforms often require adopting cumbersome stacks: custom avatar pipelines, proprietary 3D garment workflows, and deep SaaS integrations.
The Nabla Workflow
We keep it simple: you send DXF/CAD patterns and specs, we run multi‑avatar physics, and you receive updated grading plus clear fit reports, usually within hours, not weeks.
Approach
Objective analysis.
Identifies pattern and grading errors early in the development cycle.
Reduces physical sample iterations by stress-testing DXF/CAD patterns virtually.
Provides objective indicators (strain, contact points, balance) to accelerate technical approval.
Designed to complement 3D tools and physical fit sessions, not replace human expertise.
FAQ
Common Questions
Who is Nabla for and what are the technical requirements?
Our solution is designed for technical designers, pattern makers, fashion brands and grading houses. We require zero 3D knowledge and no specialized software licenses. It is a low-investment way to bring high-fidelity physics to your existing DXF/CAD workflow.
What is required to integrate Nabla into my current process?
The bar for entry is intentionally low. We only require your DXF/CAD pattern files and grading specs. We hook into your existing workflow without requiring you to change how you design or grade patterns.
How does this compare to 3D tools like Clo3D or Style3D?
Clo3D and Style3D are excellent simulators, but you still need to interpret and act on those simulations manually. We do the interpretation and correction for you. If you already use 3D tools, we complement them; if you use DXF-only workflows, we give you 3D-level insights without the overhead of a full 3D stack. If your team doesn't have the bandwidth to run and interpret 3D simulations in-house, we deliver the same level of insight as a report, without the tooling overhead.
How is this different from Virtual Try-On (VTO) widgets?
VTO tools manage a symptom. The symptom is a customer who can't find their size. The underlying cause is a grade rule that makes XL fit differently from M, and that cause was set in motion during pattern development, long before the garment reached a product page. Nabla Labs works at that earlier stage: correcting the grading so the inconsistency that would have required a VTO workaround never gets produced in the first place.
Does this rely on Generative AI for the simulations?
No. While we leverage AI for optimizations, our core engine is based on high-fidelity physics. We simulate the mechanical interaction between fabric and body across diverse shapes and dynamic postures on your behalf, sending back corrected grading and clear diagnostic reports.
Which garment categories do you support?
We support virtually all garment categories. We focus on critical functional zones (armholes, crotch, necklines) to identify where grading errors most frequently impact comfort and aesthetics, helping you iterate faster.
How do you handle fabric physical properties?
We utilize approximate physical properties based on user descriptions. We are continuously refining our material library to improve how different fabrics respond to simulation, ensuring your virtual samples behave like real garments.
Early Access Program
We are currently in a controlled early access phase. We believe in building trust through transparency and direct collaboration. Our goal is to encourage teams to stress-test our engine on their most challenging patterns to demonstrate the immediate value of upstream fit validation.
System Rollout
Early access programme.
If you manage grading or fit for a multi-size brand and you've ever had a season where edge sizes came back worse than expected, this is built for that problem. Early participants get access to the tooling, feedback on their own styles, and direct influence on how the reports and fit visualisations evolve. If you manage grading or fit and want more systematic insight than a few samples can provide, you can join the early access list below.
Nabla Labs is priced per style. Contact us to discuss volume and early access rates.