Insight - 12/19/22

Soft Goods Prototyping

8 minutes

By Rebeccah Pailes-Friedman

Soft Goods Prototyping

Soft goods design is its own special area of the design industry, and soft goods prototyping is similarly unique. At Interwoven Design we specialize in soft goods, so we make a lot of these prototypes. The process we use is particular to our studio, and to demonstrate why we like this method we’ll explain what is special about soft goods prototypes and walk you through the steps. This prototyping method can become a powerful tool even for designers who lack textile and sewing experience.

What is a soft goods prototype? 

Prototyping is an iterative process and starts with a combination of 2D sketches and 3D mockups. these first “prototypes” are to quickly asses a design idea and are used to study volume, form, access points and closures. Once the form is starting to become refined we then progress onto a higher fidelity mock-up. this article explains how we go from a paper mock-up to a fully resolved prototype that serves as a model for manufacturing. We call this final model a “high fidelity prototype”. It looks like a new product that is ready to take home and use.

The ability to create a high fidelity prototype from a pattern is the goal of soft goods prototyping.

The goal of the soft goods prototyping process is to develop a pattern that will result in a consistent, high fidelity end-result as well as to create that result to demonstrate the viability of the pattern. A key stage in this process is making a Muslin.

What is a Muslin?

We will use “Muslin” with a capital M to indicate the soft goods industrial design mock up in a basic textile as compared to the basic cotton “muslin” fabric that most often used in this process. A Muslin is a model of the design that has been sewn up in low resolution fabrics, not using final textiles, colors, or hardware. It is a specific stage of the soft goods prototyping process that helps us to test the accuracy and quality of our pattern before using final materials. A Muslin is a tool on the journey to developing a compelling prototype that allows us to work out any issues with the design before moving to final materials. It may or may not be literally sewn in muslin fabric, though it often is.

A Muslin (with a capital M) is a critical tool for testing the accuracy and suitability of a soft goods pattern.

The Brown Paper Pattern-making Method

But how do we move from a drwing and fast mock up to a pattern from which we can cut a Muslin? We use a process called the Brown Paper Patternmaking Method to create our soft goods patterns, a method developed by Interwoven Design’s principal designer Rebeccah Pailes-Friedman. In this method the designer sculpts a full scale model of the desired soft good in brown craft paper, marks it up, cuts it apart, and creates a pattern with it that is then sewn up and tested for accuracy and performance.

The Brown Paper Pattern-making Method allows a designer to go from a paper model to a high fidelity prototype with accuracy.

We’ll walk through the steps and show some examples to demonstrate the key concepts, but here is the overview of the process:

  1. Create a refined design drawing
  2. Sculpt a full scale craft paper model from the drawing
  3. Add seam lines, grain lines and cross marks
  4. Cut the model apart to create pattern pieces
  5. Transfer the craft paper pieces to pattern paper
  6. True the patterns and add seam allowance
  7. Transfer the pattern paper pieces to muslin 
  8. Sew up a Muslin and make any necessary adjustments to the pattern
  9. Sew up a final high fidelity prototype

The Steps

1. Ideate to create a refined design drawing. This process should involve 2D and 3D sketches to develop your design concept. Think about hardware, colors, and final materials as you create this drawing. Your design drawing should be a detailed and refined schematic that serves as a blueprint for the model making that will follow.  While some refinement will be possible in future stages, the drawing should be as close to a final design as possible.

A refined design drawing considers the final form, materials, colors, and features of the design.

2. From the design drawing, sculpt a full scale model in brown craft paper with masking tape or painter’s tape. Craft paper behaves a lot like a textile while holding its shape well, which is why we use it for this method. Creating the initial model is the most difficult step of the entire process. If you can get this step right, the rest of the process will flow naturally. Any adjustments that need to be made to the original concept will be made here. Anything represented in your sculpted model will be transferred to the final model, so make sure it is what you want.

Here are a few tips:

  • Starting from the “base” – sculpt the form of the model so that it looks as close as possible to the finished design – it should be the same scale and shape a your concept
  • Only use tape you can draw on. Use as much as you need.
  • Draw on your model as needed to show every detail: curves, closures, straps, pockets, handles, etc.
  • Refine your sculpture until it is airtight and exactly the form you want.
  • Edges should meet neatly with minimal to no overlap.
The full scale model in brown paper should be neatly and precisely constructed.

3. Once you are satisfied that the object fits and functions as desired, draw seam lines with a fine tip Sharpie.  Be sure to consider how 3 dimensional shapes will be created by joining flat pieces of fabric and draw a seam where the flat pieces join.  Think of how a basketball, baseball or tennis ball are made from flat pieces to create spheres. A noter good tips is to look at your own soft goods possessions to see how they are constructed.

Seam lines determine the practical construction of the form.

4. Mark grain lines (north-south lines that denote the grain of the fabric from which the bag will be made) on each of the brown paper model pieces. Add cross marks and labels to each of the pattern pieces. Cross marks will act as guides to rejoin the pattern pieces once you separate them.

Think of a pattern as a puzzle in 3 dimensions, create a guide for yourself so you can put the puzzle together again.  Cross marks are markings perpendicular to the seam lines that show where the components created by the seams connect. Give each of your pattern pieces good, descriptive label and be sure not to duplicate label names.  You can use photos to capture the construction and make a map of how the pieces fit together.

6. Cut the brown paper model apart. Be careful to cut the seam lines as straight and as neatly as possible. Use scissors or an Exacto knife to cut with precision and using a metal ruler where applicable to also help create clean lines.

IMPORTANT TIP: If your bag is symmetrical only cut the right half of the bag and leave the left half intact. You will be able to “reflect” your pattern to make a perfectly symmetrical pattern from only ½ of your model.

Adding grain lines, cross marks, and component labels ensures that you will be able to recreate the form once it is cut apart.

7. Transfer the brown paper model pieces onto pattern paper.  Double check that all of your seam lines are the same length by “walking” your seams on top of each other. This is “trueing” the pattern and ensures that the pattern will fit together with smooth seams when it is sewn up. Seams that are not the same length will not sew together correctly. There will be too much fabric on one side, and the final model will be messy. This can be avoided though careful review at the pattern stage. Be sure to transfer labels and cross-marks to the pattern paper. Once the pattern is reviewed for accuracy, add a seam allowance of ½”.

Cut with clean, careful lines to get the most accurate pattern possible from your model.

8. Transfer your pattern pieces to muslin (or your chosen mock-up fabric) and cut. In the studio, we use wax transfer paper and a tracing wheel to transfer the pattern accurately to the muslin. but you can also cut out the pattern pieces and trace them onto you fabric.

Accuracy and care is needed at every stage of this process to make sure the final result reflects the original model.

9. Sew up a Muslin and assess thoroughly. The Muslin is a test of your pattern, it allows you to resolve any issues before creating the final prototype. On the Muslin, you can add zippers, trims and plastic hardware so you can test how things work and feel. Make any adjustments needed and transfer them back to the pattern.

Once an initial Muslin is sewn and assessed, a second or third might be created to further refine the design. These changes are updated in the pattern.

10. Finally your pattern is ready for final fabric. Transfer the pattern to the back side of the final fabric, cut it out and sew up a high fidelity prototype in final materials. This final model proves the quality and viability of your pattern and it should look like it could be purchased and used immediately.

Once the Muslin demonstrates the viability of the pattern, a high fidelity prototype can be created.

Try it!

While it takes time and attention to use the Brown Paper Pattern-making Method, it is a wonderful way for those unfamiliar with pattern-making to create original patterns that can provide consistently professional results. Do you have a soft goods design idea you’ve wanted to bring to life? Try this prototyping method!


Reading Braille on a medication carton

Insight - 03/25/24

Universal Design: A Brief History and Why it Matters

8 min

Read More

portrait of industrial designer Patricia Moore dressed as an elderly woman.

Insight - 03/18/24

Design History Series N. 013

4 min

Read More

spider web with water droplets

Insight - 02/21/24

Nature-Inspired Design: A Biomimicry Primer

6 min

Read More