It depends what is meant by a bar chart.
For example, it could be that the bars are horizontal with the same vertical thickness and with different horizontal lengths, or it could be that the “bars” are vertical with the same horizontal thickness and with different vertical heights.
I put bar in quotes because, in heraldry, a bar is horizontal, the vertical equivalent being a pale. I have not, however, known of the term pale chart being used, though I have known of bar charts having vertical “bars”.
One approach is to have the bars or the pales as black and have a small amount of white space to each side of the black. That way, the bars or pales will stand out one from another as they are surrounded by white space.
If you are building up the bars or the pales from units, such as using the cell for 2 for a bar and the cell for 1 for a pale and the cell for 0 for a space, then an important consideration is rounding effects as the application uses the contours of the font to produce a pixel display on the screen.
Opinions may differ from person to person, yet I would use 2048 font units by 2048 font units for the size of each item and then have the solid black go from 0 to 2048 in one direction and from 256 to 1792 in the other. I would then display the font at any of 12, 24, 36, 48, 72 point as desired. I would avoid sizes such as 14 point as that might produce rounding effects leading to the white gaps between the pales as being uneven in size in places.
For this special purpose font I would access Font Settings… Metrics and make each value that has the word Ascent or Ascender in its name 2048 and all the rest as 0. I do not fully understand what the metrics with Gap in their names do, yet I have found that setting them to 0 seems to do no harm. That seems to set up the vertical measurement.
For the horizontal measurement: in the Glyph Overview window, right click on a glyph, then choose Properties… from the menu that appears and set Advance Width to 2048.
Using 0, 1 and 2 is a suggestion for a basic font. Once the basic 2048 font units by 2048 font unit size for the item has been established, there could be other items added to the font. For example, 3 to enable half a unit to be added to the top of a pale and a 4 to enable half a unit to be added to the right-hand side of a bar.
Using such a font, diagrams should be producable using Microsoft WordPad.
A font of my own that uses a similar technique, not for bar charts but for designs built up from units, is my Style Art font.
It is a free download and is featured in the Style Art Font thread in the Gallery forum.
I hope that this helps.
William Overington
21 November 2009