There have been only two or three occasions in my career when I've needed to create a curvy vector line for a design in Photoshop. Each time it took me much longer than I anticipated. I'm not sure why, but what seemed like obvious approaches before always turned out to simply not work as hour upon hour went by. I finally found a way! The best method I've found so far is to use the Line Segment Tool in Illustrator to create a straight line. Then use Filter >, Distort >, Zig Zag. Be sure to select 'smooth' for the line. Be careful not to use the ZigZag inside of the Effects dropdown but instead confirm you are in the Filter dropdown before applying the distortion. You should be able to copy/paste into Photoshop as a smart object now. I'm glad this has turned out to help so many other folks! I owe you a huge thank you!! I'm a huge fan of the blend tool in Illustrator – use it all the time. I also dig zig zag. I stumbled on to your tut and it inspired me to combine the two and holy cr*p! For months I've been looking for an app or filter that generate's guilloche patterns like the one's found on currency. Don't need it anymore. I can create my own. Mine eyes have seen the glory. I can't believe I never thought of combining those tools before. I just had to say thanks. But now I have created my wavy line, if I group it with my logo and then resize the whole lot the waves retain the formatting from before and don't resize proportionally - is there a way to stop this from happening? I'm assuming you mean you grouped it with your logo while still in Illustrator...? Not sure how to avoid your issue. If you resize it in Illustrator the curvy line does get a bit funky. But if you copy to clipboard from Illustrator at normal size and paste it into Photoshop as a Smart Object, then resize in Photoshop, it resizes with the ratios intact. Maybe you can save it back out from there as a Photoshop EPS or somehow get it back into Illustrator if you need to. after you made the squiggly line with the filter, choose Object ->, Expand appearence and it becomes a full vector I've used illustrator for YEARS and it's part of my profession, but just came upon the need to create a wavy, consistant line. and was like... what? There has to be an easy way to do this and you helped. This helped me so much today! I spent 3 hours yesterday trying to get my lines smooth and curvy...this took less than 5 minutes! You're awesome! John's work for us was great! Replied promptly to our email messages and was easy to reach via phone when we needed clarification. The results of his work were exactly what we were looking for. Source.