Parametric vs Interpolated fonts


I'm currently studying about parametric fonts and interpolated fonts, and there's something that I can't quite understand. In his article, James Shimada (2006*) says that Multiple Master and TrueType GX fonts are a form of parameterized outlines. These are the same as parametric fonts? 

Parametric fonts are a sort of automated design, but can be Multiple Master and TrueType GX parametric fonts either?

Thank you



  • Hrant H. PapazianHrant H. Papazian Posts: 1,349
    edited May 16
    Parametric means the outlines are a result of calculations based on variables. Interpolated is at a lower level: outlines are "canned" instances between designed masters.
  • Thomas PhinneyThomas Phinney Posts: 1,403
    edited May 16
    Parametric fonts are not really “automated design,” in my opinion. They are a label for a group of technologies.

    An individual parametric font is a font which can be varied within some parameters. Although no doubt some day the design portion will be automated, today there is still actual design done by a human to create each parameterized font.

    In some parametric technologies (for example, Font Chameleon), an individual font once set up can then be varied even in ways beyond what the designer explicitly dealt with in detail. But even then it is only because that capability was baked in from the beginning. In most parametric technologies, the designer has to explicitly create each design axis. (Yes, slight simplification. One can for instance use a weight axis plus anisotropic interpolation to create a first draft of a width or contrast axis. But most axes are not so easy to get to—and even when they are, they usually need fixing after the initial creation.)

    Depending on the model, it is sometimes possible (for example in GX and OpenType Variations) to have axes that interact beyond what the designer has explicitly explored and controlled. However, absent great care by the designer, this may result in corners of the design space that have... problems.

    I have worked a fair bit with parametric fonts, going back to my Master’s thesis in this area twenty years ago. Currently wrestling with a five-axis parametric font. It is simultaneously fun and painful!
  • Ana_FAna_F Posts: 3
    Thank you both for the answers. They were helpful  :)
    Depending on the model, it is sometimes possible (for example in GX and OpenType Variations) to have axes that interact beyond what the designer has explicitly explored and controlled. 

    GX and OpenType Font Variations are both hint-based, right? The designer designs a single master and establishes a maximum value for point positions and then the values are interpolated to get instances. How can the designer have axes that interact beyond what he has explicitly explored and controlled?
  • Ana_FAna_F Posts: 3
    I talked about "hint-based", because I read that TrueType GX technology used hinting and instructions to move points:

    "(...) Our initial attempts to create variations from a default font were to use the TrueType instructions themselves. The thinking was that most of the features we wanted to vary between (a Regular and a Bold, or a Regular and a Condensed) were captured in the instructions that controlled elements like stem weights, serif lengths and thickness, heights and alignments, and so on. But while we could create variants that looked bolder, or more condensed, the designers among us always wanted to tweak something in the shape in a way that the basic TrueType instructions did not allow. Then Mike considered the Delta instruction. (...)" Tom Rickner, 2016*a

    and in the conference he gave in Typo Berlin, he said:

    "We tried to create Times Bold out of the Roman. And we tried to do this with hints, with instructions. So, code. We are not drawing this. We are trying to describe the changes in certain parameters.” Tom Rickner, 2016*b (This was one of the things that confused me with parametric fonts)

    So, if I understood correctly, first, they started using the hints and then considered the delta instruction that move points in any direction (not just x or y) with vectors. But isn't the delta instruction considered a hint?

    The designer designs all the masters they want to, and designates one as the default. In the compiled font, the other masters are represented by deltas to the point positions. Values are in essence interpolated (or created by vector addition if not between the master designs, for example if the masters are not in the corners of the design space).


    So what that means is that in GX/OTvar, if I design a regular master in the middle, and also:
    - Condensed
    - Expanded
    - Thin
    - Black
    ... then a “black condensed” can be created by vector addition. You could call it extrapolation, but it is within the design space defined by the black and condensed masters.

    - Besides the master, that needs to have complete outline data, the designer has to provide the extreme values, and then the values are interpolated.
    - And if the designer needs a black condensed, values from the master, the black and condensed versions are interpolated. 

    I'm correct?
    And is the same process in GX and OTVar?


Sign In or Register to comment.