From Beat...
Hello,
Thank you Beat for your last answers.
Some more questions for Beat please:
(01)
I asked what the functions for CVTs 94, 95 and 96 were?
Beat answered: Which ever basic dimensions of LC serifs you want to use them for.
However, in the MS web article 'From typeface to font file', they seem to be for the LC i & j dots. The para reads:
'In the lowercase CVT group, CVTs are predefined for the i, j dot distances. The X distance is the horizontal dot distance, the first Y distance is the vertical dot distance and the second Y distance is the white space from the top of the i/j to the bottom of the dot.'
As CVTs 94-96 were the only ones that I could not find a use for, I assumed that they are the ones referred to above. If they are not, then which are the 3 CVTs mentioned in the article for the i & j dots?
[Beat Stamm] If that's what said document suggests, then this would be a good use for CVTs 94 through 96.
(02)
If a CVT number is unused, any need to delete it?
If left at a zero value, it is ignored?
[Beat Stamm] No need to delete it. If it's the last CVT (cf. also Q#11), then deleting it may make the final font file marginally smaller.
(03)
CVT 65:
Often LC Y distance, but could it be used for any smallest Y distance?
Eg. the thin circle around the Registered symbol?
[Beat Stamm] 65 tends to be used as "grand-parent" CVT, from which 66 (X) and 67 (Y) are "derived," but this is not mandatory.
(05)
Best resolution for Windows would be 96 dpi?
[Beat Stamm] Yes. This corresponds to the "small fonts" setting (Windows Display properties => Settings => Advanced). However, many users leave VTT at 72 dpi in order to include all ppem sizes.
(06)
Is there anywhere a detailed list of the function of each standard CVT?
[Beat Stamm] Not to my knowledge. Like I said, the CVT as supplied with VTT is merely a suggestion.
(07)
How are 'Absolute' & 'Relative' defined in terms of VTT?
[Beat Stamm] This has to do with CVT "inheritance" and how the CVT value is specified. Absolute specifies the actual value (e.g. width of a straight stem, cap height), relative specifies the amount by which the value differs from the value it relates to (e.g. width of a round stem is so-and-so many units more or less than the straight stem, overshoot is some number of units more than the cap height).
(08)
Is it better to round measurements up/down to whole values for the CVT?
[Beat Stamm] Not necessarily. Why make e.g. the main lc straight stroke 170 or 160 units, if it really should be 165?
(09)
Why are the pixels measured in eighths?
[Beat Stamm] 1/8 of a pixel is the default resolution by which such features as deltas or minimum distances are specified. Other resolutions can be used, such as 1/4 of a pixel, or 1/16.
(10)
What is the difference between the 2 lines of sample text?
Nothing in 'Help'.
I recall something about 'Plain' & 'Printer or Fractional' spacing when I used TypeMan.
[Beat Stamm] The top line is using the linear advance widths, i.e. the advance widths that have not been modified as a result of hinting (e.g. by deltaing the right side-bearing point). The bottom line is using instructed advance widths. This permits to see the effect of hinting on spacing and on how close you'll get to a reasonable wysiwyg.
(11)
Lastly, how do I find the next available CVT ID number should I wish to add one?
[Beat Stamm] Unless you wish to "re-cycle" unused CVTs, the next available CVT is indicated in the title bar of the CVT window. It says "### entries", and since we start at 0, this is the next available number.
