### Latex math: Vertical bar

Like that used for indicating the evaluation of integrals between limits:

\bigg|

as in

\frac{\rho}{4\pi}\left(-\frac{1}{r}\right)\bigg|_{r_{0}}^{\infty}

from a hint here from robphy

1. Great stuff, thanks

2. Thumbs up!

3. Thanks a lot!

4. Awesome, this is just what I needed! Thanks a lot.

5. Thank you so much!

6. Thanks!!! :D

7. Just what I needed!

### Flowing text in inkscape (Poster making)

You can flow text into arbitrary shapes in inkscape. (From a hint here).

You simply create a text box, type your text into it, create a frame with some drawing tool, select both the text box and the frame (click and shift) and then go to text->flow into frame.

UPDATE: