Text on Line
You can draw line, then double click and add some text to the line.

But what you really want is to have the text at right angles to the line so that get some meaning from it. Consider the following example where the interface names have been added to the lines for a physical / VLAN diagram.

Rotate the Text
SO what we really want is to be able to rotate the text so that it is perpendicular to the joining lines.

And now we have something much more appealing and relevant.

When the text box isn’t the right size or the right angle
One problem with this technique is that Once you put a dot or full stop on the line that text automatically wraps around or that the text boox is not quite the right size for the text you want to put there. This diagram shows the text wrapping when a full stop is added:

Using the Text Block Tool
Changing the font to a smaller size and using Arial Narrow is usually good enough but the best alternative is to use the Text Block tool. Select the line or object before you head to the menu, select the Text and click the drop arrow on the right of the button:

which will then put resize bars on the object – like so:

This text block tool not only allows you to resize the text width, but also to rotate it to non-standard angles. By grabbing the round green dot with your mouse, you can rotate the text box to any angle you want.

And you can change the width of the text box by grabbing the green squares:

There are some related tips to formatting the text background in this article which you might want to look at.
Suggestions on using this technique
I tend to use this a lot when drawing diagrams that need to capture the physical information such as switch port numbers and router/firewall interface names. The combination Layer 1/2 information is really useful for network diagrams.
Credit
Big thanks to Ray and Marko in the comments for the tip about the Text Block Tool which I didn’t know about. I have updated the post with this detail.
Other posts in the series
- Colour Blindness, Network Diagrams and Reliability
- Network Diagrams: Rotating Text on a Line (This post)
- Network Diagrams: Tips for Printing from Visio
- Network Diagrams:Zones on a diagram with Visio shape union
- Network Diagrams: Drawing complex VLAN Networks with IP Addressing
- Network Diagrams: Drawing Freehand Curves (and then fixing them)
- Network Diagrams:Aligning Shapes
- Network Diagrams:Locking the Background Shape
- Network Diagrams: Labelling an VLAN/IP Segment
- Network Diagrams: VLANs and IP Subnets
- Network Diagrams: Drawing the Background Shape
