Knotwork Tutorial-Line Treatments
To this point we've been simply using black to cover up the
construction marks (dots, circles, or diamonds at the grid points)
and filling in the bands with colors. The Celtic scribes
certainly used this technique in the original manuscripts.
They also used many other techniques to decorate the bands.
Some of these are covered below.
Try increasing the circle diameters/diamond
widths without changing the grid spacing to construct thinner
bands, and making smaller circles/diamonds to help get wider
This pattern is from [Meehan2], originally from
Durrow. Here is the original grid size, and a
band generated using this template.
Here is a grid with larger diamonds generating a
This grid uses smaller diamonds and, consequently,
wider bands. Note that some spaces between bands
disappear with wider band widths. Sometimes the bands
will need to be adjusted to compensate for this effect.
Band Edge Effects
Besides changing the width, bands
themselves were often decorated.
The band edges were often drawn in black, letting the
background parchment show through.
Bands often had lines or dots running down the
...or two narrow bands running on the sides of the
Finally, the knots were sometimes simply drawn with
red dots alone against the parchment.
Celtic work was incredibly colorful.
Some knots were light on dark (as most of the examples), but some
were dark on light backgrounds. Colored areas were used on
the bands and in the middle areas (between the bands) as well.
Even if a band was continuous, often more than one color was
"Doubling" Interlace Patterns
"Doubling" can be considered a line treatment that forms a
parallel double band from a broad interlace pattern; the two
new bands do not cross except where the original broad band
did. This form of interlacing was quite popular with the
scribes and was extensively used in both Lindisfarne and
Construction techniques developed by George Bain(see [BainG]) involved
building the original wide interlaced band, then converting the edges of
these bands into new, narrow, parallel bands, and finally fixing up the
interlacing. This requires a lot of erasing and
fixing. Doubling can be supported with the cell
structures we've been using by following the procedure below:
1. Draw original pattern on double-sized cells compared to the
desired final results. This 10X2 cell pattern is taken from [BainI]
page 101, and was originally from Lindisfarne Folio 11B.
2. Build a set of "half-sized" cells between the original
points. I used smaller than half-size diamonds for band
spacing here to reflect the Lindisfarne style of
doubling. See [BainI] pages 71-72 for further information
and alternative construction techniques. On the
illustration, the new cell diamonds are in green. Add back the
original interruptions (extra "walls") pattern.
3. Add interruptions to the new patterns (in the half-sized cells)
based on the original, full-sized cell patterns. When converting from single
to double interlacing, there are eight possible patterns or cases to be
handled. In all the case descriptions, the single knotwork cells are in dark
blue, the doubled cells are light blue, edges are dark blue lines, the original
(single) interruptions (walls) are in grey, and the new, added, doubled
interruptions are in dark red:
Case 1: Uninterrupted cells along the edge of the original
Case 2: The original template has an interruption in the border
between two cells that is not on an edge.
Case 3: The original has an interruption added next to a
Case 4: The original template has a corner along two edges (at
the end of the overall pattern).
Case 5: The original has a two-sided corner along an edge.
Case 6: The original template has a corner not along an edge.
Case 7: The original pattern includes a corner that crosses two cells
(a nested corner) along an edge.
Case 8: The original template includes a single cell corner next to
4. Determine, for each interruption and edge in the original, the doubled case
that describes the interruption. For the Lindesfarne F11B pattern we're using as
an example, the following figure shows the doubled case for each part:
5. Add the new interruptions according to each case found. The added
interruptions are shown in dark red.
6. Interlace as usual. Curves will take a bit of extra planning in order to
keep them parallel and at a constant width.
7. Color the bands as desired. The illustration is colored to highlight the
continuity of the bands across the repeating, doubled pattern.
Also see other examples of doubling provided on the
Celtic Art pages.