Ink bleeds are commonly used for transitions and reveals in video editing.
You can find nice ones online either for free or paying.
But sometimes you need ink bleeds which are more suited to
your needs (be it resolution, shape, timing, ...) and you have to rely to generate yours.
One of the famous issue you'll encounter when designing and printing technical parts with a 3d printer is the small difference between the dimension of your designed holes and the physical part. This is due to the lack of so called arc compensation.
The great NopHead made a point in figuring out precisely why ...
You might have been looking for the developer grail like I did recently :
hack away your code
have continuous integration server perform all automated tests on a virtual machine and tags your code as "good to push on production" (or for the most crazy adventurous, having your code pushed to prod)