Note: This is part 1 of 3
- Varnishes in the Rain 1: Canvas Preparation and Painting
- Varnishes in the Rain 2: Varnish Making, Consistency Testing, and Application
- Varnishes in the Rain 3: Testing in the Rain
Table of Contents
Varnishes in the Rain 1: Canvas Preparation and Painting
Canvas Stretching and Priming (I)
Name: Tianna Helena Uchacz and Naomi Rosenkranz
Date and Time:
2018.05.03
Location: Chandler 260 (Making and Knowing Lab)
Subject: Canvas Stretching and Priming with Rabbit Skin Glue and Burnt Sienna
Background
- This is the first installment in a series of lab experiments that will test claims in Ms. Fr. 640 about the ability of particular varnishes to withstand the rain or fail in it. Building on protocols from previous experiments in the Making and Knowing Lab, we will stretch, prime, and paint canvases for eventual varnishing and outdoor testing of those varnishes.
Aims
- Stretch the canvases and apply first priming coats in staggered layers
Set-up & materials
Protocol
- Following a procedure previously undertaken in the Making and Knowing lab under consultation with Erma Hermens (Rijksmuseum), we will stretch raw canvas over a wooden support, fasten it with staples, and prime it with the following staggered layers:
- 2 thin coats rabbit skin glue (RSG)
- 1 thin coat burnt sienna (BS)
Oil Paints |
Name | Ratio | Ingredients | Purpose |
Burnt Sienna | Prepared oil pigment | | Ground layer |
Process & Observations
- Stretched canvas over prefab 12x12” frames; secured with staple gun
- Warmed rabbit skin glue in bain marie
- Applied rabbit skin glue to canvas with brush, leaving slight margin on all sides raw
- Applied burnt sienna over the dried glue with a brush, leaving a 1” strip of untouched glue
- Left canvases in fume hood to dry
Canvas Priming (II)
Name: Tianna Helena Uchacz and Naomi Rosenkranz
Date and Time:
2018.05.07
Location: Chandler 260 (Making and Knowing Lab)
Subject: Canvas Priming with Lead White
Aims
- Finish priming the canvases with a thin coat of lead white (LW), leaving a vertical strip of the BS uncoated
Set-up & materials
Protocol
- Apply a thin coat lead white (LW) to the canvases, leaving a strip of RSG uncoated at the right
Oil Paints |
Name | Ratio | Ingredients | Purpose |
Lead White | Prepared oil pigment | | Ground layer |
Process & Observations
- Burnt siena layer dry to touch
- Applied lead white over the burnt sienna, leaving a 1” strip of untouched burnt siena
- Left canvases in fume hood to dry
Painting
Name: Tianna Helena Uchacz, Naomi Rosenkranz, and Solena Le Moigne
Date and Time:
2018.05.11
Location: Chandler 260 (Making and Knowing Lab)
Subject: Painting
Aims
- Paint the primed canvases with a variety of colors and patterns so that we can better assess the effect of the varnishes that will eventually be applied on top and weather treated
- Pigments were chosen to represent a range of colors and types of pigment:
- Blue verditer: a mineral pigment of copper carbonate prepared as a synthetic version of the naturally-found ore, azurite
- Madder lake: an organic pigment that is the result of precipitation of dye on a substrate typically a translucent pigment used as a “glaze” in oil painting
- Yellow ochre: a natural earth pigment which is durable, inert, and lightfast; typically very opaque and resulting in a more matte finish
- Dots
- Diagonal stripes
- Curviform waves
- Areas of dragged out pigment
Set-up & materials
Protocol
Oil Paints |
Name | Ratio | Ingredients | Purpose |
Blue Verditer | Ratio: 3:2 pigment to oil | | Top-most layer, colored oil paints |
Madder Lake | Ratio: 3:2 pigment to oil | | Top-most layer, colored oil paints |
Yellow Ochre | Ratio: 16:13 pigment to oil (approx. 4:3) | | Top-most layer, colored oil paints |
Process & Observations
- Lead white layer not completely dry
- thinner areas dry to touch
- thicker areas still tacky to wet; paint easily transferred to finger
- Decision made to apply oil colors to maximize drying time
- Three colors of paint prepared by mulling pigment with linseed oil:
- Pigments were prepared according to the ratios described in the table above
- The ratios were determined by adding linseed oil in small amounts to the dry pigment in a plastic cup, mixing with a paintbrush, until the paint was a consistency like that of honey.
- The paint was then transferred to a glass plate and mulled with a glass muller until smooth and homogenous.
- For ease of painting, each paint was then added to a clean plastic container (that could then be capped and the excess paint stored for later use if needed).
- Identical tripartite pattern drawn with pencil on lead white section of all three canvases
- Pencil tip sinks into thicker, wetter areas of lead white, creating slight channels
- Paint applied in different ways in each section to help show how varnish coating affects interaction of water with paint layer
- Left section: dots of each paint applied using butt of #2 size paintbrush
- Center section: alternating red, blue, and yellow chevrons
- Right section: nested blue and red crescent moon shapes; yellow center with pigment pulled fan-like out across lead white ground
- NJR, THU, and Solena each paint one canvas
- Note: painting the canvases took approximately one hour and as more time passed, the pigments began to settle and dry slightly in their containers. The madder and verditer settled more severely, resulting in quite a thick almost solid layer at the bottom with a thinner oilier layer on the top. As possible, the paints were mixed and the layers incorporated to ensure more consistent painting across all sections and canvases.
- Left canvasses in fume hood to dry
