It’s the Italic/Bold checkboxes on the first page of the FontInfo dialog.

If Font Validator reports that “your subfamily is Light” then you did the naming wrong. On FontLab Studio’s first Font Info page, in the Style Name field, only four names are allowed: Regular, Bold, Italic and Bold Italic. Obviously, one of your fonts has “Light” there. That’s wrong. You should put the true typographic style names into the OT Style Name field on the second Font Info page. But I thought I actually wrote this on the FontLab forum.
A.

Thanks!
I think know I get it. What should I put in the Styte Name field for XXX Black? Bold or Regular?
And for XXX Light? Regular?

Sloppy reading on my part, sorry ...
If ’Black’ is already part of the black weight’s Family Name, then the according Style Name would be ’Regular’. Similar for the light weight. Since you get the error message even with the bold weight, you seem to have forgotten to check the Bold checkbox in the bold weight. (Whereas it should be unchecked in light, regular and black weight.)
This however would only be true if you intend to link regular with bold, but treat light and black as separate families on the level of Family Name / Style Name. Given your description, I am not sure if you followed the tips & tricks’ PostScript Type 1 or the OpenType section.

Hi K.L. & Adam,

The family has only 4 members: Light, Regular, Bold, Black and no italics (it is a display font with no italics).

For TTF fonts shall I put different Family Names for Light and Black?

Or can I have Light and Black under the same Family Name than Regular and Bold?
(Reading ’Learn FL Fast’ -pag. 130- gives me the impression that the four members should only be Regular, Italic, Bold and Bold Italic in TTF.)

Thanks in advance.

> (Reading ’Learn FL Fast’ -pag. 130- gives
> me the impression that the four members should
> only be Regular, Italic, Bold and Bold Italic
> in TTF.)

Wrong impression. This limitation applies to TTF and OTF.

A.

Ramiro,

typically, you make the typographic “Bold” style act as a style-linked bold for the typographic “Regular”. (The style-linked bold is the font which is chosen when the user clicks on a “B” button in an application, or hits Cmd-B / Ctrl-B).

So you typically have:
OT Family: XXX, OT Style: Regular,
  Family: XXX, Style: Regular
  Font is bold: no
OT Family: XXX, OT Style: Bold,
  Family: XXX, Style: Bold,
  Font is bold: YES

Then for your typographic “Light” and your typographic “Black”, you really have two choices (I’ve italicized the differences):

Solution 1: The Black font is on its own
OT Family: XXX, OT Style: Light,
  Family: XXX Light, Style: Regular
  Font is bold: no
OT Family: XXX, OT Style: Black,
  Family: XXX Black, Style: Regular
  Font is bold: no

Solution 2: The Black font acts as the style-linked bold for the Light font
OT Family: XXX, OT Style: Light,
  Family: XXX Light, Style: Regular
  Font is bold: no
OT Family: XXX, OT Style: Black,
  Family: XXX Light, Style: Bold,
  Font is bold: YES

It’s really up to you, but I’d say in this case I’d go with solution 1.

However, if your family had the typographic styles Light, Regular, Medium, Bold, Black, then you might consider making the Black font act as the style-linked bold of the Medium font, and leave the Light without a style-linked bold, or you could make the Medium act as the style-linked bold of the Light font, and leave the Black on its own, or you could make the Light, Medium and Black three independent fonts without any style linking. It’s a design decision, really.

Adam