Fontcreator setup

FontCreator - Font Editor FontCreator - Discussion
1

I’m trying to familiarize with FontCreator . I would like to create from scratch and/or modify letters with a specific measurement.
Around the creation area I see values ​​but I have seen that this values change when I zoom in or out.
What exactly do they are/measure (image below)?
Around1.png
When I enable the grid I couldn’t understand what size is each square (inside the grey grid)?
grey grid.png
How can I set up the area (where the letters are created) for example setting up the area in 10mm x 20mm) as shown in the figure below?
Stup_Area.png
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Thanks

2

Font Design does not use cms or inches or points. The units are relative to the number of font units / em (2048 by default).

See Frequently Asked Questions, and the grid options on the Tools menu.

3

The values shown in the rulers represent the internal grid of your font. These are not absolute physical dimensions but rather units relative to the font’s design space, also known as “funits”.

When you zoom in or out in the Glyph panel, you’re changing the visual representation of these funits on your screen. The numbers on the rulers scale accordingly, but the underlying font units remain unchanged.

Units per Em
The entire design space is defined by the “units per em” value, also known as “upem”. It is available at the Font Properties panel. This value can be anywhere between 16 and 16,384, though common and recommended settings are:

TrueType fonts and OpenType fonts with TrueType outlines: Usually a power of 2, typically 2048 units per em (or sometimes larger like 4096 or 8192 for very detailed designs).
OpenType fonts with CFF based outlines: Often set to 1000 units per em.

The “em” square is the reference frame for all measurements in the font. For example, if you’re working with a 2048 units per em font, a glyph that is 1024 funits tall is essentially half the “em” square.

Converting to Physical Measurements
The internal funits can be related to physical measurements (like millimeters) via a conversion factor that involves the output settings. The key formula is:

Scale = (point_size × resolution) / (72 × units_per_em)

This formula is used when converting values from the font coordinate system to physical sizes. It’s important to note that 72 points equal 1 inch, and 1 inch equals 25.4 mm. Resolution refers to the number of dots or pixels per inch (DPI/PPI) that are used when rendering the font. All devices like on-screen displays and printers have their own DPI.

If you are going to print the font, then assume the printer resolution of 72 DPI. If you want to know the scale to convert between funits and mm, use this:

Scale = (25.4/72) × (point_size × 72) / (72 × units_per_em) = (25.4 × point_size) / (72 × units_per_em)

So if your font has upem set to 2048 then if you print at point size 24, the Scale will be:
Scale = (25.4 × 24) / (72 × 2048) = 0,004134115

The height of 800 funits will then be:
800 × 0,004134115 = 3,307291667mm

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4

Thank you for your reply.
I am not an expert and I see that the thing is more complicated than I thought. I have to evaluate very carefully what you write me.

In the mean time is there a way to simplify? Will be possible to force the program to set the rectangle (where to build the letters) to use a specific measurements so setup the rectangle for example at 10mm wide and 20 millimeters high (Baseline & CapHeight ) . In this case I know that inside it the letter will have those measurements.
If I understood well all is setup as a default and there is not way to force the program to convert the unit present on the sides into for example millimeter then how can calculate to convert for example CapHeight 1434 in to 20 minnimeters?
Once done how can I move this red dotted line to the desired height (I tried to move it with the cursor but it doesn’t move)?
DImentions.png
I ask because the letters should be passed to lightburn program and then printed by laser engraver on metal so they must have a specific width and height.

5

The conversion between funits and the actual size on your device depends on the font size and resolution.

In FontCreator, the red dotted lines represent crucial metrics—often the CapHeight or another key baseline—and are linked to the font’s metrics rather than being freely movable on the canvas.

Instead of trying to drag them with your cursor, you need to adjust the metric values directly in the Font Properties panel on the Master tab.

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