---
title: Parametric pattern design
order: 10
---

The FreeSewing core library is a toolbox for **parametric pattern design**;
Using parameters or variables to manipulate the outcome of a given design.

In sewing patterns, the parameters are what is provided by the user: 
Their measurements and options that they have selected.

<Note>

##### No more grading, ever

When drafting or designing patterns or garments, it is common practice to start 
with a fit model (or dress form). 
The measurements of the fit model are used as input in the initial design.

Adapting the pattern for a different model is a tedious task, 
which is why patterns are graded up and down to cover different sizes.

But in a parametric sewing pattern, adapting to different sizes or models *just works*.

</Note>

FreeSewing patterns are implemented **as code**, which has a lot of advantages.

It allows for patterns that adapt to your measurements or preferences, 
fine-grained version control, seamless collaboration, and using existing
patterns as a starting point for you own, to name but a few.

That being said, you don't have to be a code monkey to use FreeSewing.