Using brushes to create pipe/rope guidelines (digital tutorial)

[Suuper-san]

I thought I would finally share one of my "secret" techniques, that I can't say I have seen other artists use, although it's not like I have been looking around much. If you've seen it elsewhere then it's not my intention to claim the patent on it XD
It's not really a secret haha since I have mentioned it in my art thread and it's visible in my sketches :P

It's a (digital) technique to quickly create guidelines for tubes,pipes,rope, mostly long and thin, winding things. The technique can be expanded to other things as well with a little imagination and the correct choice of brushes.
It's a bit more than a tip so it gets it's own thread :)

Basically you use a semi-transparent brush, the thickness of your pipe/rope, and just draw the path it takes. Then when inking, you can then trace the edges of your brush stroke to get the 2 edges of the pipe. Here's a simple example:



And another one, with a bit of a cable detailing:


For simple lines such as this, it might seem a bit overkill, as you could probably line it up by eye, but it becomes more useful when you have more complex paths, or interacting objects, such as a cable wrapping around something, or bangles worn on an arm etc. In this instance it helps to draw the entire object, including the parts that are hidden by the object in front of them, to help the lines to all be pointing to the right place and have continuity.




You need to use a bit of intuition to know which lines to trace, but it's quite simple really. Working from the front-most objects to the back-most prevents accidentally drawing a line somewhere when it should have been hidden by an object in front of it.

And here is a cable spiraling or twisting around itself. This could be useful for hair drills, plaits and other hair styles, mechanical parts like springs etc.



And finally, some proper practical applications, some of which you might have seen in my sketches:

Using a brush (with pressure-size dynamics) for tapering octopus tentacles: (not done too well!)



Lace or ribbon in clothing:



And finally, my favourite - shoe laces!





The reason for using a semi-trasparent brush becomes a lot more clear in the ribbon and lace examples - where the parts overlap you can still see all of the details. A solid brush would lose detail and make it impossible to trace the lines where overlaps happened, like below:



Here are some of my WIPs in which I have used the technique, to give you an idea of how it normally looks and is used in a sketch: (click to enlarge)

As ribbons and shoe laces guidelines:



As a fabric/clothing pattern guideline:



A large circle brush for a ball/sphere:



While I haven't quite perfected this method nor explored it's many possible applications, it's proved useful enough already that I am confident to suggest it as a way to speed up initial sketches, and create more accurate guidelines for inking. You can also use different brush shapes i.e. a square brush, to get different pipe shapes. You could also use different brush colours to remind yourself of different materials or to separate different parts of your design if it is complicated.

Feedback is appreciated as always, I'd be happy if this was useful to anyone, or if you have any more ideas on how it can be used!