That's a good point - using it almost anytime there's added thickness and mostly straight lines. Purses, etc. I've got one that I can use with my Janome. But then I've got another Singer one that came with the piece of junk Singer plastic machine I bought 20 years ago. (it NEVER worked right, I deep sixed it). I saved the walking foot and have tried it on the 15. It works. But it's kinda cheesy. Still it works. I've heard of the OEM Singer walking feet (the penguins) but have never seen one for real.