Clinton in front of the projector operating a mouse
Clinton Blackmore created Project & Cut to solve the issues he was having with calibrating his projector for sewing patterns.

It’s a sign of a robust and vibrant online community when its members build new tools that benefit everyone, and other members of the community help improve those tools through feedback over time. That’s just what’s happening in the projector sewing community.

Using a projector to project sewing patterns onto fabric speeds up the pattern cutting process of sewing and has been described by those who do it as revolutionary. The Projectors for Sewing Facebook group now has over 73,000 members from around the world sharing their setups, troubleshooting, and inspiring one another. When the community was first building momentum in 2020 Canadian data scientist Charlotte Curtis developed a tool that solved a primary problem members were facing. In the same way one would tape together printed pages, PDFStitcher digitally converts a PDF of separate pages into a single large file that can be viewed on a projector. Members of the group have expanded on the documentation since then, adding new features and translating the software into multiple languages.

Now, two other Canadian developers are tackling another difficulty sewists face when using a projector: calibration. When setting up a projector for sewing, a projector needs to be manually calibration to ensure that measurements in the projection match the source as closely as possible. For sewing, this means making sure that the pattern pieces you see on the cutting mat are accurate and not distorted. Manual calibration can be successful, but it’s also a delicate process that can prove frustrating. That’s where Clinton Blackmore and Courtney Pattison have come in. Each of them, separately, has developed software tools that quickly and easily calibrate a projector accurately every time automatically.

Pattern Projector

“It was my husband’s idea,” says Courtney about her projector calibration desktop application for sewing. The couple had been painting murals in their home in Kitchener, Ontario, for a few years, projecting the image on the walls.

“The first one we did we tried without doing any sort of calibration. We just set it up and did a first pass. And then we went to set it up again and realized everything was out of whack. It was a pretty big fail and pretty big frustration.”

courtney pattison in front of sewing machine
Courtney Pattison created Pattern Projector to make her temporary sewing setup easier to calibrate.

After taking a break of about a year, her husband, a software developer, began playing with OpenCV, an open source computer vision and machine learning software library, to solve the issues they were facing with their projector. He was successful.

“I had no idea projector sewing was a thing,” she says, even though she had been sewing for several years at that point. When she opened one of the digital patterns she’d bought and noticed it had a projector file, she got curious. That’s when she found the Facebook group. “There was no way I was going to try and set up my projector and calibrate it manually for sewing because I have a temporary setup,” she says. “I really wanted to make this tool for myself.”


One of the things her husband had found in OpenVC was how to get a perspective transform. This allows you to input the width and height of your cutting mat and then drag the four corners on the screen to match your mat. When you drag those corners, it often isn’t a rectangle because your projection is probably not completely straight on your mat. The program changes those four corners that are a little bit wonky into the correct size rectangle.

The tool she created, Pattern Projector, is a browser-based application so that it’s available to everyone everywhere. “All I’ve done is applied it for projector sewing,” she says.

The project came at a perfect time for Courtney. After six years as a stay-at-home mom, she was ready to reenter the job market. She wanted to take on a project that people would use and provide her with feedback so that she could go through the whole process of making and launching an app that could be part of her portfolio.

calibration process
Pattern Projector is a browser-based application that is open source and free to use.

The reaction to the app, she says, has been overwhelmingly positive. “If there are any issues, the group has been really good at helping me to figure out what the problem is, helping me to reproduce it so I can fix it.”

Courtney’s aim was to get a minimum viable product launched as quickly as possible and then work with the community to develop the features they wanted. Users have contributed back to the code base. On the day Pattern Projector launched, for example, an American [SM1] [MOU2] member of the group named Hannah, contributed to the open-source code and “basically redesigned the site” and implemented inch support. (Courtney had only included centimeters in the hurry to get the app launched and was grateful for this addition.) Other users inverted the projected lines, making them green and thus easier to see. “I would never have thought of that,” Courtney says. Everyone who has contributed has been added to the Pattern Projector GitHub group so that they can all see updates coming through. Charlotte Curtis of PDFStitcher has also contributed. 

Pattern Projector is essentially a viewer “with lots of sewing niceties added to it.” There are no plans to enable users to save anything within the app. Once a user downloads it, everything is done locally on the user’s computer. “I prefer to keep things simple,” she says.  

Courtney doesn’t plan to charge for Pattern Projector, opting for it to be a portfolio piece for her rather than a revenue generator. “It’s open source and free to use. Somebody else could just host it and it would be in the state that it’s in now.”

application screen
Project & Cut can be downloaded and used locally on a computer. Like Courtney’s app, users drag the four corners so that they match their mat and the software automatically calibrates from there.
clinton cutting a sewing pattern
A computer programmer by day, Clinton Blackmore took up sewing during the pandemic.

During the pandemic, Clinton Blackmore’s wife suggested he learn to sew. “She said it required precision and attention to detail. I thought, okay, I’m good at that.” He checked a few books out of his local library in Southern Alberta, watched some YouTube tutorials, and got started using his wife’s sewing machine. By day, Clinton is a computer programmer and he really enjoyed having an off-screen hobby. He made a hat, a dress for his wife, and pajamas and a Halloween costume for their young son.

Clinton had some prior interest in projectors before he began sewing. A few years ago, he’d admired some jack-o-lanterns while trick-or-treating. “They were singing and talking,” he remembers. The effect was done with a projector using a technique called projection mapping. “I thought, oh, that’s slick.”

These two new interests came together when Clinton discovered projector sewing and joined the Projectors for Sewing Facebook group. He bought a projector, set it up on the ceiling of a room on the first floor of his house, put a cutting mat on the floor beneath it, and began calibrating. Not only was the process tedious, when kids ran around on the floor above he had to adjust it again. Clinton quickly realized many other members of the group were also struggling. That’s when he got an idea.

“I thought, oh, this would be so simple. You just need to do projection mapping. Specify the corner, specify the size, and you’re done.”

He found the idea irresistible and got to work making a desktop app that would make it easy for everyday sewists to quickly, easily, and accurately calibrate their projectors every time.

The app building began with some sample code for projection mapping. He explains the concept this way, “In a video game where you’re running around, there’s the whole world. Well, what actually happens to put it on the screen is that you, and the entire world, are moved to the origin. You’ve moved to the center and the world is moved around you. That’s very much the same math.” Although he thought developing the app would be relatively simple, the math proved challenging and Clinton’s brother-in-law, who has a PhD, lent a hand.

closeup of projector surface
Both apps also have built-in rotate and mirroring tools, as well as the ability to select size layers, great features for quickly projecting and cutting sewing patterns.

His app is called Project & Cut and it can be downloaded and used locally on a computer. Like Courtney’s app, users drag the four corners so that they match their mat and the software automatically calibrates from there. Both apps also have built-in rotate and mirroring tools, as well as the ability to select size layers, great features for quickly projecting and cutting sewing patterns. 

Project & Cut frees users to take the projector down from its mount and use it to show movies or for other purposes. “I’ve seen people ask, hey can we take the projector down and watch a movie and put it back and the answer was don’t touch it.” Now, the answer can now be yes which means the projector is a much more versatile machine to own.

Clinton plans to monetize Project & Cut. Data from a recent user survey indicated that a $20 one-time purchase would be reasonable to most. “If you’re serious about projector sewing, for the price of a few projects that you want to make you can buy this additional software and as long as you have a computer and know how to use a keyboard and a mouse, you can use it.

Courtney agrees. Her Courtney’s projector was $50 plus the $15 for a ceiling mount. With her app, she says anyone can get started with projector sewing.

“If you can sew, you can figure out how to do it. If you can work a sewing machine you can do this. Working a sewing machine is a learning curve!”

In regards to Clinton’s app, Courtney welcomes the competition. “I think there’s definitely space for both of us to try ideas and throw things out there and see what works,” she says. Seeing his preview video pushed her to finish and launch her app, for example. “I feel like that’s only better for the community,” she says.

Clinton echoes her feeling. “Learning about Courtney’s new tool was a huge surprise to me. While I’ve been working away on my project, she’s been working on hers. The dawning age of the quick calibration tool is a definite win for projector sewists everywhere.”

Abby Glassenberg

Abby Glassenberg

Abby co-founded Craft Industry Alliance and now serves as its president. She’s a sewing pattern designer, teacher, and journalist. She’s dedicated to creating an outstanding trade association for the crafts industry. Abby lives in Wellesley, Massachusetts.

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