Four ways to digitise your paper and hand-drawn sewing patterns

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If you have had your patterns made manually on paper, to take that and convert it to a digital pattern, you have to "digitise" it.

WHY WOULD YOU NEED TO DIGITISE?

1. To grade your patterns digitally

Many patternmakers still draft patterns by hand, but grading is now done predominantly using CAD software. To grade a hand-drawn pattern digitally, it must first be digitised.

While patterns can certainly be graded manually, CAD software allows grading to be done more efficiently and accurately. Marker making is also much faster in CAD, and digital files can be stored, reprinted, and reused whenever needed.

2. To reduce physical storage

Digitizing allows you to keep digital copies of your patterns and potentially free up valuable physical storage space.

3. To share or sell patterns online

If you intend to offer your sewing patterns as PDF downloads, they will need to exist in a digital format.

METHOD 1: USING PROFESSIONAL DIGITISING TABLES

Digitizing tables are typically set up in conjunction with professional and quite expensive CAD systems. As a result, this setup is not the cheapest and may be beyond the reach of many.

The physical pattern is secured to the digitizing table, and an input device is used to trace around the pattern. Each CAD system generally supports only specific digitizing tablet models.

Below is a YouTube video showing pattern digitizing with Lectra.

Where can you find this service?

You may be able to locate agencies or service providers that specialize in pattern digitizing and grading around you and take/send the physical pattern to them. Once your pattern is digitised, they can usually grade it and create markers if needed. 

This method is best if you need your pattern converted into standard industry formats such as DXF AAMA/ASTM, which can be read by professional CAD programs.

If all you require is a format compatible with generic vector drawing software such as Adobe Illustrator, Affinity Designer, CorelDRAW, or Inkscape, this may not be the most suitable option. While some CAD programs can export files that open in these applications, the resulting files often contain disjointed lines and excessive nodes, making direct editing difficult.

METHOD 2: TAKING PHOTOGRAPHS AND IMPORTING THEM INTO YOUR VECTOR DRAWING/CAD SOFTWARE

This is a very popular method among indie sewing pattern designers and home sewists because most people already have access to a smartphone camera.

The process typically involves photographing each pattern piece as level as possible, either by using the camera's levels function or mounting the camera on a tripod. Before taking the photograph, a test square is usually drawn on the pattern, or the pattern is placed on a gridded mat to provide a reference for scaling.

The photograph is then imported into vector drawing software, where the pattern is traced using the software's drawing tools. Before or after tracing, the image is resized using the test square or grid as a reference.as imported photographs are usually much larger than life size and must be scaled down.

The downside of photographs

No matter how carefully photographs are taken, there will be some degree of distortion to pictures taken. This makes accurate digitization difficult in generic vector drawing programs such as Adobe Illustrator or Affinity Designer.

You may have seen videos of indie pattern designers digitizing from photographs, but a lot of fiddling and correction has to be done to get the pattern right. If you choose this method, it is advisable to take direct measurements from the physical pattern and compare them with what appears on screen, even after the image has been scaled. 

This method may be acceptable if:

• Accuracy is not important.
• You have access to the physical pattern to measure from.
• You do not mind measuring and adjusting numerous lines and curves.

‎As a freelance patternmaker who also digitises patterns for others remotely, I do not use this method as I get sent the photo files only. Even if the client provided me with the dimensions of every curve and line, or the physical pattern, the amount of on-screen adjustment required is a big no for me. I might as well draft the pattern from scratch.

An exception: CAD programs with photo-digitizing capability

Some CAD programs dedicated to sewing patternmaking, also support photo cameras and/or pictures, and these programs typically have built-in technology that compensates for the photo distortion in ways generic vector drawing programs cannot.
The CAD software that I use includes this capability, and it is how I digitise patterns from photographs.
Below is a video of  my process of digitising photos in my CAD software that has module for digitising from photos.

 

UPDATE: While writing this blog post I discovered that I can use photo-editing software like Photoshop and other similar apps to correct the distortion in the picture using "Perspective Crop" before importing into the vector-drawing software.
With this additional step, I am more comfortable recommending photo digitising in vector drawing software.
Below is  a video on how I use Photopea, a free web-based photo-editing app, to correct the same photo I used in my CAD software. For this to work properly, your sewing patterns should be photographed against a grid mat (or a rectangular background with known dimensions) so you can use the grid lines to get the correct perspective.

METHOD 3: SCANNING THE PATTERN

This is my most preferred method for patterns to be digitised in Vector drawing software. The pattern is scanned using an actual scanner (not a phone camera) and then imported or placed into the drawing software, and traced using the drawing tools within the software. With scanning, 99% of the time,  you do not have to resize or scale the pattern, so there is less fiddling to do and zero distortions to contend with.
Below is a video showing how to digitize a scanned pattern in Affinity Designer, a now free design program.

What I Did in the Video

• I opened the scanned pattern sheet in Affinity Designer (or any similar vector-drawing software).
• Before tracing, I changed the document units from pixels to inches in the Document Setup menu.
• I then used the Measure Tool to check the 2" × 2" test square that I had drawn on the pattern, ensuring that the scan had been imported at the correct scale.
• Using the Pen Tool (P), I traced the pattern by drawing straight lines around its outline.
• I then used the Node Tool (A) to adjust and curve the lines so that they matched the contours of the paper pattern.
• For better visibility in the video, I changed the stroke colour from the default black to red and increased the line weight.

Option 1: Use a copy shop
Copy shops near you may have large-format scanners that can accommodate full-size pattern pieces.

Option 2: Scan in sections

If a copy shop is not within reach, then scan your pattern in sections or tiles. This may take a bit of a learning curve. Once you figure out the best way to scan in sections with your regular scanner, the sections will be placed in the drawing software and stitched together in the software, much like you assemble printed A4/Letter tiles. 

Below is a YouTube video by PatternLab showing his method of scanning in sections.

 

 METHOD 4: DIGITISING WITH THE AID OF A PROJECTOR

For sewists already familiar with projector sewing, a projector can be used for digitising with a reasonable degree of success.

Project your computer screen on the wall (or table), open your vector drawing software and manually calibrate the projector within your vector drawing software. Software designed for projector sewing, such as Pattern Projector, will not assist with this process because it is intended for projecting PDF patterns rather than projecting vector drawing software.

Once calibrated and you have found the correct percentage of zoom, Tape your pattern to the wall. While looking at the wall, use the drawing tools in the Vector Drawing software on your computer, trace around the shape. You will need great eye and hand coordination to do this. The lines and shape you draw around the shape will then show up on your screen.

Pros

• Relatively accessible if you already own a projector.
• Large pattern pieces can be digitised easily.
• Once calibrated, tracing is relatively quick.

Cons

• Manual calibration can be time-consuming, especially if you do not have a permanent setup. You may need to recalibrate every time, which can easily take 30 minutes or more.
• Accuracy depends entirely on calibration. If the calibration is off by a few millimetres, the digitised pattern will be off as well.
• Your workstation needs to be positioned close enough to the wall projection for you to see the paper edges and internal details clearly.. A high contrast between the paper and background helps considerably.

Projector-assisted digitising is great if you can tolerate minor inaccuracies of a few millimetres here and there.‎ Personally, I wouldn't use this method for clients' jobs, but for personal projects.

I have personally tried all of the methods discussed above except digitizing tables. Although my CAD software supports them, I do not have access to one. The setup cost is high, and given the alternatives available today, I do not consider them essential for my work. I also do not have access to large-format scanner, although some of my clients have access to one through copy shops local to them.

I hope this blog post has given you a clearer understanding of the various ways to digitise sewing patterns, whether you are a hobbyist, sewing pattern designer, or professional patternmaker, or even if you simply plan to outsource the work.
What other ways do you know a paper sewing pattern can be digitised?

My next post will be all about Digital and Computer Aided Patternmaking software- the types and options available to you at different price-points, and more.