#Amstelvar Documentation

##I. Introduction

###Overview AmstelvarAlpha-Variations.ttf is an exploratory OpenType 1.8 font made with a combination of font bureau's python standard-based font tools and a Google font tool requiring two or more font styles with compatible contours, and meta-data concerning the relationship of the font styles that forms two or more styles into a style axis. The font produced is a Variation font, containing a default font, and the cumulative styles designed to be interpolated between default, and among and the styles of the axis.

###Design Amstelvar is a serif typeface design with references to oldstyle and modern typeface designs and so is apt for uses requiring such a style. Variation technology adds adeptness to the design for use at many sizes, with variety of weights, and widths at any size, as well as grades (a change of weight without change to width), another variety via a contrast axis, E.g. control over the difference between horizontal and vertical strokes and finally for all the glyphs, an axis to flatten the serif rise, changing the style from old style to slab serif. For the lowercase and selected glyphs with relation to the lowercase height, there is also an x-height axis.

###Specification notes The design is produced on a 2000 unit per em grid, in quadratic Bézier curves and contains overlapping contours. The "Alpha" tag is indicative of the lack of a substantial glyph repertoire, currently only contains ASCII, as well as lacking any glyph positioning, glyph substitution, or conforms to the entire new open type 1.8 specification. This includes new tables of great importance including the stat table.

##II. The axis of AmstelvarAlpha

###Overview

The 5 axis are a combination of "registered" and unregistered axis that either contain one or two styles in addition to the default, or regular style, in forming their axes. The regular style itself is designed as a 12 point size master, "medium" weight, and wide, with low contrast for this style of type, as is apt for the size master. The axis are given unit per em values for the parametric change embodied in that axis, as is representable by one value, along with the required, -1, 0, +1 for UI presentation.

###The Axes

1. A normal weight axis, or the progress of weights in a traditional font family don't have a single definition for the way their parameters are manipulated from regular to black or regular to thin, but the general definition of the weights of a typeface is they are changing how heavy or light the style is, without changing its apparent width, x-height or the angles of it strokes.

The Weight axis of Amstelvar is parametric, or the progress of darkening and lightening only effects those parts, and as much as possible does not effect other parts, particularly the white space. So as Amstelvar gets bolder or lighter on the weight axis, the internal white spaces of the letters remain consistent, leaving their control to the width axis. This is also the only current Amstelvar axis that uses two styles, one thinner than the regular and one bolder than the regular.

-1 is 10/2000, 0 176/2000 and 1 is 1000/2000, or half the em.

2. Normal width axes, or the discrete styles within typeface families, seek to maintain the same characteristics of the wider or narrower styles with whatever changes to contrast and weight are required for the given width, usually being used at a different size, and often being used at a very much larger size than the regular style, for headlines, e.g.

The Width axis of Amstelvar is a reciprocal parametric axis, relative to the weight axis. It simply controls whitespace, reducing from the regular width, to very narrow white spaces inside and on either side of the glyphs. It leaves the weight of the main stems as a parametric a match to the regular as well as leaving the contrast the same as the regular causing minimal collateral loss of blank space, except more beneficial like the length of serifs. The axis currently only uses one style that takes it in the narrow were direction relative to the regular.

-1 is a white space of 84/2000 and 0, the default font has a white space of 804/2000.

3. Unlike the axes above contrast is not a registered axis in the opentype font format. But variety in contrast has a rich history in type styles of many scripts, ranging from the subtleties of contrast's presence in most common sans serif fonts, to its obvious presence in type with ultra-thin serifs and connecting strokes, as if under the direction of a sharp writing tool, and then into the showdown realm of reverse contrast, and reverse stress type styles.

Amstelvar's Contrast axis provides only higher contrast (thinner contrasting strokes), relative to the default. It's effect is on the serifs, without changing the serif rise axis, and many horizontal strokes, collecting into collateral effects on the internal and external white spaces of letters as the contrast increases.

0 is the default contrast and is 100/2000, and -1 is high contrast and 8/2000 units per em.

4. An optical size axis normally mixes parametric values, (as do “normal” width and weights in a typeface family of static styles). In “normal” optical sizing, the lowercase height, the weight, contrast and width, all vary to form the adapt style of a font, be they for readability at small sizes, or for compact and impactful use in large sizes.

Contrary to an optical size axis, the x-Height axis of Amstelvar only modifies how tall the lowercase is, a subset of the parametric values that vary in optical sizes, along with width, weight and contrast.

-1 has a lowercase of 890/2000, the default lowercase height is 1000/2000 and the +1 is at 1200/2000.

5. The Serif Rise is not a registered axis, and has one required function in the style as designed, to lighten the serifs in the second of two ways. the first control is added into Contrast, giving the design space control over the height of the serif base, and this axis controls the diagonal rise of the segment connecting to the main stems, both straight and curved.

-1 has a serif rise of zero units and the default is a rise of 35/2000.

###Design space, User Space, and the combinatorial explosion of deltas.

1. The eight styles currently creating the Variation font’s design space encompasses a large number of combinations of the 5 axes. The delta values of the main axes, weight, width and contrast, cover quite large ranges for each of those parameters respectively. So the design space of Amstelvar is quite large compared to what most font families contain stylistically, and…

2. There currently is no difference between the design space, and user space, which is allowed by the new font format, but not yet implemented.

3. 5 full axis, i.e. with style change at both -1 and +1 in each axis, combine to create 120 extrapolated styles of effected by from 2 to 5 axes. There are two instances in such an example with all five axes at +1, and all five axes at -1, and then a lot with just four at +1, and one at -1, and so on. I’d call these, in an example 5-axes variation font, duovars, triovars, quadravars, and the two pentavars.

4. Axes with collections of extreme deltas often create wild contours as the deltas add up in ways not intended by the type designer. Part of this wildness is not finding the exact right position for every control point in the entire design space, and some wildness is uncontrollable as a result of the delta range, or the need tof intermediate instances to tame the contours. One immediate solution is the type designer’s intervention, correcting the extrapolations and adding them back to the design space where the result of two or more axes would otherwise extrapolate incorrectly. Amstelvar contains some corrected duovars in the design and user space, but in this early alpha there is plenty of qualitative wilderness around the edges of things.