Setting Initial Control Values

Preparing the font creates the template for the ‘cvt’ table. All the important control value numbers will be there, along with the hexadecimal number and other comments such as:

/* STEMS: UC, STRAIGHT, X */

However, the control values will be 0, to be supplied by you. Before hinting a font, you need to measure all the glyphs in the font and fill in the template.

First, disable the Grid Fit and Pixel display so the control values will be in F-units. You can do this either by clicking these option on the General Options submenu of the Display menu, or by pressing Ctrl + G (to disable gridfit) and then Ctrl + B (to disable pixels). Next, open the ‘cvt’ table in its own text window. Based on what’s listed there, use the Measuring tool to measure all glyphs or representative glyphs (H, O, f, g h, o, x) in F-units one at time for standard heights and distances, such as the cap height for all uppercase glyphs. You’re measuring the outline, which shows the original design, because the bitmap version might not correspond exactly. Usually, the stroke weights and other spatial relationships vary slightly from glyph to glyph.

As you measure a representative glyph, write down the result, which is the top-right value in the status bar. This can take some time for an entire font, but doing this accurately is very important. The Measuring tool ensures precise values and streamlines the repetitive measuring needed to determine ‘cvt’ values.

Finally, enter the dominant values in the ‘cvt’ table. When you finish, compile the cvt table (Ctrl + R), and save (Ctrl + S), so the TrueType rasterizer applies these new values to the font (see “Compiling Your Results”).

To fill in the ‘cvt’ template

1.       On the Views menu, click Control Values, or press Ctrl + 4.

2.      Resize and position the Control Value Table window so you can see it while working on a glyph in the main window.

3.      Click in the main window (or press Ctrl + 1).

4.     If already selected in the General Options submenu of the Display menu, click to clear Grid Fit and Pixels, or press Ctrl + G then Ctrl + B

5.      Select the Measuring tool by either clicking its icon on the toolbar, or press F9. Referring to the values listed in the ‘cvt’ table, use the Measuring tool to measure all glyphs (or representative glyphs) in the font for a specified feature (say, dominant uppercase stem width in the X direction).

6.     In the ‘cvt’ table, locate the appropriate comment for the feature measurement you have just taken, and replace the 0 value with the value you measured for the feature.

7.      Repeat Steps 5 and 6 for each value in the ‘cvt’ template.

8.     Compile the Control Values by selecting the Compile submenu of the Tools menu, then clicking Control Values, or by pressing Ctrl + R.