How To Convert Paper Patterns for CAD/CAM & CNC

Updated Jan 25, 2023
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PublishedJun 7, 2018in CAD, Converting to DXF
Paper pattern on dark background - Converting paper patterns

Industries around the world make use of paper patterns to quickly prototype their cutting designs. From car seat manufacturers to shoe designers, paper patterns are vital to the design and manufacturing process. In some cases, industries—or individuals—will painstakingly create hard-copy paper patterns one by one. But what if you want to speed up the process by taking your paper pattern to CAD or CNC? There’s one simple solution: convert (or digitize) your paper patterns for CAD.

In Scan2CAD’s latest guide, we look at what paper patterns are and how they’re used in different industries. We also give you the full lowdown on how to convert paper patterns for CAD or CNC—offering a free trial of Scan2CAD for your troubles!

Table of Contents

What are paper patterns? 

Paper patterns are essentially cutting templates of a required shape and size which will be cut out of material. They communicate the necessary information and directions to produce prototypes—taking note of design, shape, fit and measurements. Much like an architect uses blueprints to create structures, paper patterns are used by industries to create prototypes and eventually, a final product. 

Fundamental to industries across the world, paper patterns are used for a variety of purposes, from producing garments in sewing and fashion design to manufacturing car seats in the automotive industry. While these patterns are usually made with paper, it’s not unusual for industries to use paperboard, cardboard or plastic if they’re in need of something a bit sturdier.

Paper pattern for garments example

Image source: Stylus Apparel Group

How are they used?

The process of making paper patterns is otherwise known as “patternmaking” or “pattern cutting”. To start, designers will sketch or trace over their chosen shape. An example of this might be a glass company which will head to a site and trace the shape of client patterns on cardboard paper. Next, the designer will cut the shape out of the paper—giving them a paper pattern. 

Some companies might opt to use their paper pattern manually, using the template to cut their material. Most industrie, however, opt to digitize their patterns—converting paper patterns for use in CAD or CNC. We’ll discuss this particular process below and the benefits attached. Once digitized, the paper pattern can be opened up and modified in a CAD application—meaning changes can be made swiftly and efficiently. If happy with the final design, the pattern can be sent to factories electronically for production or sampling.

Why convert paper patterns for CAD?

Before we look at how you can convert paper patterns for CAD (hint: it involves Scan2CAD), we’re going to look at the reasons why industries opt to digitize and convert paper patterns for CAD. 

Converting a paper pattern with Scan2CAD – Watch the full tutorial in this post, below.

Easier and faster modification

Converting paper patterns for CAD ensures changes are faster and easier to make. If you’re working with physical paper patterns, even small changes can push you back weeks. In large industries, this can be a nightmare. Having to redo or revise paper patterns—due to mistakes or changes to the design along the way—wastes time and reduces the chances of meeting deadlines. If you convert to CAD, however, you can make the necessary changes without having to go back to the drawing board. 

By working with paper patterns in CAD, it can be easy to create several sizes of the same design to fit particular shapes—if you’re working with garments, for example. Additionally, it’s possible to use old designs—take elements you like—and create brand new designs. This is something that would take much longer with physical patterns. In all, converting to CAD can streamline the production and manufacturing process, meaning faster layout and cutting.

Greater collaboration

Collaboration can be difficult if you’re working solely with physical paper patterns. The physical transportation of paper patterns from companies to factories can be long and laborious. Additionally, mistakes can happen along the way. More often than not, designs are never perfect the first time around. Companies and factories mailing physical designs back and forth for corrections slows production time down and can lead to miscommunication.

If you convert paper patterns for CAD—digitizing them—you can make necessary modifications quickly and in real time. With cloud-based CAD, it’s even possible to work with colleagues—no matter how far away—in real time. Patterns can be worked on simultaneously between colleagues—enabling designers to enact fast revisions. Once happy with the final result, patterns can be sent to cutting for production. 

Better management

Physical patterns can often get worn down depending on their material. If you have a template of a dress that you keep going back to for reference, then odds are that it will begin to wear down with time. This means that sizing and measurements might end up skewed as a result. If you digitize your patterns, however, you don’t have to worry about them degrading with time. They can be kept safe and organized—ready for print or cutting at any time. 

By deciding to convert paper patterns for CAD, you can take advantage of consistency with sizing, standardized patterns and a library of easily accessible patterns. An added bonus to a digital archive of patterns is that you can save up space that may have otherwise been taken up by physical copies. 

How do I convert paper patterns for CAD?

There are many services that you can find online that will convert your paper patterns for you. Some ask you to scan your patterns and others require you to send it to them by mail. If you’d rather do it yourself, however, we’ve got the perfect solution: Scan2CAD. How does it work? It couldn’t be simpler…

  1. Sketch or trace your shape
  2. Cut the shape out of the paper
  3. Scan your pattern
  4. Convert using Scan2CAD
  5. Use your design in CAD or send directly to a CNC cutter

Before we look at how Scan2CAD can convert your paper patterns for you—and other methods of conversion—we’re going to look at what conversion is and how it works. 

What does conversion entail?

Image of a manually traced letter So, you’ve got your scanned copy of your paper pattern. How exactly can you convert it to create a digitized copy? Conversion—or vectorization—can be enacted through manual or automatic tracing. Much like the process of creating a paper pattern, manual tracing involves drawing over your paper pattern with vector lines using an image editor. Automatic tracing, by comparison, consists of using a specialized software that traces over your pattern automatically.

If you’re working in a big industry, e.g., manufacturing car seats in the automotive industry, you won’t have time to convert your paper patterns manually. It can be time-consuming and can get in the way of tight deadlines. Automatic tracing is fast and, in some cases, can take mere seconds to complete! 

Once your paper pattern has been converted, you can save it in a vector file format that can be worked with in CAD. Typically, DXF is the go-to format. Why? It’s a universal file format that can be used in most—if not all—CAD packages. This is highly beneficial in terms of collaboration. Exporting to a common format like DXF mean that you can send patterns to your colleagues—or directly to factories—and know that they’re be able to open them. 

Conversion methods

Image editors

Logos for Inkscape, Illustrator and CorelDraw You might be surprised to find that some of the image editors you undoubtedly work with can be used to convert your paper patterns. If you prefer to manually trace your patterns, you can simply open your pattern in the editor and trace over it with vector tools. Alternatively, many editors have an automatic tracing tool—at the click of a few buttons, you’ll have a vector image. Here are a few examples of image editors that you can use: 

If you’re only converting the occasional paper pattern and you have time on your hands, there’s probably nothing wrong with using an image editor. That being said, if you have a large volume of patterns to convert, we’d recommend using a specialized solution. 

Online converters

You don’t have to look far to find an online converter that promises to convert all of your patterns for free. As with most things in life, however, it’s far too good to be true. These converters might be free, but that advantage comes with an abundance of problems. For starters, you’ll only be able to upload designs that have a small file size. In terms of the actual conversion, you can expect poor quality and issues with text. 

One of the biggest problems with online converters lies in security. When you download files from the internet, you run the risk of downloading a virus or Trojan. Additionally, you don’t know who else might end up having access to your patterns. 

Scan2CAD

Scan2CAD is a market leading raster-to-vector conversion software. This means it can convert your scanned pattern—a raster image—to a vector file format like DXF that’s ready for use in CAD. The software supports a wide variety of file types—from raster file types like JPG and TIFF to vector file types like DXF and DWG. 

So, how does the vectorization process work in Scan2CAD? Once you’re happy with your scanned image—using pre-conversion tips we’ll discuss below—you need to select your vectorization settings. Then, the software will automatically detect the lines or shapes and trace over them with vector lines. The actual conversion process can take seconds.

Converting with Scan2CAD

Acquiring an image of a pattern

As with any conversion, it’s of the utmost importance that you use a suitable image. What does this mean? It’s simple, really. You can’t just take a low quality photograph of your pattern on your phone and expect the quality to be suitable. Instead, we suggest using a scanner to acquire a high-quality picture of your paper pattern. 

Once you’ve scanned your pattern, we suggest saving it as a TIFF. This raster file format gives users the best possible output for conversion. It comes with lossless compression, so you can expect high resolution and quality even after you’ve made edits to it. 

Video: Convert paper patterns with Scan2CAD

In the following video we’ll take you through all the steps required to convert your paper pattern to an accurate vector outline using Scan2CAD. 

View video transcript

In this tutorial, we will be converting this paper pattern or template to a vector outline. Now, you may have heard this described as digitizing or vectorizing. That’s exactly what we’re doing in this case. One of the most important parts of the process is to ensure that you’ve got a suitable quality image to be converted. In this case, I have a paper template which is being cut out of card and it’s quite light, so I’ve placed it on a dark background. I have some dark material and scan the image with that. The reason I placed it on a dark background is, it’s important to have some level of contrast in color between the object you want to convert, I.e., this paper pattern and the background. If you had a dark pattern, then you could use a white piece of paper in the background. Usually if you just place the item directly on the scanner, if you are scanning the object, then you should be fine.

I do regularly see some images of paper patterns or these kind of manufacturing templates which are not suitable for conversion, that’s usually due to the image being taken with a camera. And it’s a photograph that may be dark, low quality, and even skewed. It needs to be perfectly parallel to the object, and if it’s not, you have dimension skewed. So it’s important that the image is suitable. Once it’s suitable, we can convert it using Scan2CAD, and there’s two or three steps. One, to clean it, then to convert. And then the third step, if you want to, is to edit the drawing in Scan2CAD. We’ll go through all those steps now. First, we need to clean the image to make it suitable for conversion. To do that, we use the Threshold tool which converts it to black and white. And what I’m also going to do is negate the image, so I click the Negate tool under Adjust. And the reason I’m using the Negate is it’s easier when you have a white background and a black object you’re converting. So we’ll click Okay.

We can see there’s lots of holes in the image, holes are white areas within black areas that’s due to the speckles on the original card. And we can remove those by going back to the Raster Effects, choose the Remove Speckles and Holes, and I’m gonna move the slider for Holes all the way up to the maximum. Click Okay. And the image is now suitable for conversion.

We’ll click the Vectorize icon, we choose Outline because we want an outline of the image, and I will choose Bias to Angulars because I want to preserve the angles rather than the curves in the image. And the vectors I want to create in this case are polybezier, we’ll click Run, and that gives us a vector preview of the vectorization or the digitized image. We can see the results here and if we want to, we can see it with the Raster image below, and that looks perfectly accurate. So I’m happy with that and I’ll click Okay.

So we now see the results. I could turn off the Raster image in the View options down the bottom here. So we’re just viewing the vector image and we can edit this however we want now. We could even reload the original Raster image to compare the accuracy. What I’ll do first is change the colour of this vector by going to View Vector Colors. That option’s just out of this video ’cause I’ve got my toolbar at the top here. Then I’ll reload the Raster image by going to File, Open, I’ll choose the original image again. I don’t need to save the image. You can see now we’ve got the Blue Vector outline and it’s perfectly accurate to the image.

So at this stage we could, if we wanted to, input vector dimensions. Let’s say, for example that you know that this paper pattern is perfectly 20 centimeters from this point to this point, we’d choose Snap to Endpoints, click the Measure Tool, and click from this point to this point. Because we chose Snap to Endpoints, it will snap to those vector ends. And we’re gonna say that that equals 20, the unit of measurement, centimeters, click Okay. And now we’ve inputted the correct dimensions for this image. To save this out now, we just go to File, Vector Save As, and you could save it out as a DXF or DWG, whatever you may require.

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