Highlight surface scratches on a gessoed icon board by rubbing in red ochre pigment
St Hilda (c614-680) showing adjustments I need to make to head and shoulders
My homework for the next diploma session, is an icon of St Hilda, referring to an image painted by Aidan Hart. The icon can be seen further below and also on his website Aidan Hart Icons. During my childhood, Whitby was a favourite seaside destination from our home in York. The sight of the ruined abbey looming over the cliffs was a vivid landmark against what was often a cloudswept sky. This dramatic photograph courtesy of Mark Davis Photography shows how the abbey forms such a striking silhouette against the east coast sky.
To think that St Hilda founded an an abbey and community in this wild landscape is remarkable and gives an insight into the strength of her character.
St Hilda of Whitby by Aidan Hart
For this icon, I am using a flat plywood board. I will oil gild the halo so the sanding only needs to be taken as far as 600 grit sandpaper. If you over-sand the gesso, the paint won’t stick. I’m using an icon board which I gessoed last summer which I also sanded up to 120 grit paper. With hindsisght, I should have sanded it right up to 600 grit, as it is much easier to work outside in the warm than indoors in a UK January! Sanding gessoed boards is a dusty process so be prepared. Put a few sheets of newspaper over your worksurface and have your vacuum cleaner and a dust mask to hand. You will also need a medium sized dry paintbrush to brush the gesso dust out of the sandpaper, a cork sanding block and all the different grades of sandpaper to hand. Looking back on Dylan Hartley‘s notes which he gave us at our gessoing session last year (click here for a pdf copy SANDING ICON BOARDS by Dylan Hartley), Dylan reminds us that you should choose a place to sand where there is raking light ideally with one main light source. This helps to show up anomalies and scratches. The first sanding is done with 80 grit paper, then work up through 120, 180, 220, 320, 400 and 600 grades. It is important to use these in sequence and ensure that any grooves left by the gesso brushing are smoothed away.
Splitting sandpaper sheets and filing them by grade
In the UK, sandpaper is sold in sheets about A4 size. I hadn’t realised until Aidan showed us, that if you fold and tear the paper in half lengthwise, then tear these strips into three, you can get six pieces ready to wrap around your block. Given that you go through sandpaper very quickly, it is worth spending time folding, tearing and filing the different sized papers into envelopes which does helps the flow of work.
Keep brushing off clogged sandpaper
It is really important to brush the sandpaper often – as soon as you have sanded the board a few times, lift the block and brush. You can also vacuum up the clogged paper to save dust clouds forming. The whole process is a bit of a faff as my glasses steam up when I wear a dust mask and they get covered with dust! Rubbing in a pinch of red ochre with cotton wool is a really effective way of seeing where the scratches are hiding. Even with good raking light, it is easy to miss a scratch until you start painting – and they are difficult to disguise later.
Identifying scratches in gesso by using red ochre pigment
Looking closely at the photo above, you can also see the horizontal marks made from clogged up sandpaper.
Icon board finished to 600 grit paper ready for painting and oil gilding
That’s the board now ready for me to trace on the drawing. More on that next time. Thanks for reading! Ronnie
PS To see a demonstration by Dylan Hartley gessoing icon boards – there is a clip on You Tube here