Experiments with different metal points for drawing and the effects of oxidisation

I have been experimenting with drawing using a variety of different metal points and how they oxidise, and my results so far are laid out in the illustration and table below.

Different metals make subtly different marks and have different tonal ranges.  My drawing in the illustration of fritillary buds and leaves was made using seven different metal points.  I used a traditional off-white bone ash ground.  With time the metals oxidise, producing subtle and varying changes in colour.   The time taken to oxidise depends on the atmospheric conditions to which the drawing is exposed, for example if a drawing is framed and sealed, this will limit exposure to oxygen and the time for oxidization will be much longer.  The seven metals I used in the drawing and my findings were as follows.

  1. Nickel: This is quite a hard point to work with; it had a limited tonal range producing a soft grey mark. Nickel faded almost completely with time.
  2. Brass: This made a mark rather darker than that of nickel although the tonal range was still limited. Brass turned a yellowish gold and appeared to fade a little with time.
  3. Aluminium: This had a greater tonal range, produced a coarser line and did not blend all that well. Aluminium as I expected showed little colour change with time.
  4. Gold: This produced a lovely soft grey mark, blended smoothly and well and although the tonal range was quite narrow. Gold did not change colour with time.
  5. Copper: This blended quite well; it was a little coarser than gold to draw with although had a slightly better tonal range. Copper turned greenish with time.
  6. Silver: This had a good tonal range and blended well to produce lovely soft greys.  Silver turned to a warm brown and darkened with time.
  7. Bronze: This had a limited tonal range. Bronze turned a greenish yellow and lightened with time.

                  

Tests using 7 different metal points and a drawing of fritillary buds and leaves using each of the 7 different metal points showing the effects of oxidisation:

[A-Nickel, B-Brass, C-Aluminium, D-Gold, E-Copper, F-Silver, G-Bronze]

The article showing these experiments can be seen in the SBA book Botanical Painting by Margaret Stevens

Margaret Fitzpatrick 2021