Attics and Basements and Closets, Oh My! Part 17: Paintings

​While those of us in the conservation department grapple with the many challenges facing our society, we are finding comfort in our family heirlooms and treasures—many of which require our attention. We understand that like us, many of you may be turning to your family treasures for comfort during these trying times. Thus, the conservation department would like to share tips on ways to care for your personal collections and assure you that we are here to support you and the collections that you hold dear. 

Each week a different student from the Winterthur/University of Delaware Program in Art Conservation will address ways to care for the collections in your cupboards. This week’s post focuses on the care and storage of paintings and was written by rising second-year Paintings Fellow, Katelyn Rovito.

Paintings 

My loving parents still proudly display some of my earliest and mildly embarrassing paintings throughout their home, and my hoarding tendencies have led to piles of art schoolwork stacked up in my childhood bedroom and our family storage unit. Whether you’re displaying your adult child’s Picasso-esque portrait of grandma or a real Picasso from your priceless modern art collection, there are things you can do to ensure the long-term preservation of a painting.

What is a painting?

Paintings are complex layered structures. Simply put, paint is made of pigments mixed with something sticky like oil, acrylic, glue, egg, or even milk protein (known as casein). Various materials from rocks to copper have been used as supports for paintings, but the most common supports for Western paintings are wood panels or canvas. Canvas, typically cotton or linen, is a fabric that’s typically stretched around a wooden, adjustable ­­­stretcher or strainer. It’s common for artists to start by sealing the panel or canvas with an animal glue followed by ground layers before beginning the actual paint application. Depending on the artist’s preferences, ground and paint layers can be composed of the same media or mixtures of different media. Lastly, some paintings are coated with a varnish that both protects the paint and enhances the surface gloss.

​Environment

The tricky thing about preserving paintings is that each of these layers reacts to environmental changes differently. When a flexible canvas expands and contracts with humidity, the more rigid layers of oil paint on top of it can crack. Wooden panel supports are also prone to dimensional changes and can warp and split during extreme humidity shifts. Luckily for us, paint is typically happy in the same conditions that we are. Our advice is to avoid storing your paintings in spaces where the environment is constantly changing, like a garage, an attic, or my parents’ storage unit. To minimize structural damage, keep your paintings between 40 and 60% relative humidity (RH). Light is also important to avoid as it can fade certain pigments and speed up varnish discoloration. If possible, don’t hang a painting in a location that gets direct light. Paintings might look nice hanging above a fireplace, but be aware that soot can accumulate on the surface, and heat from the chimney behind the painting accelerates degradation reactions. 

​Frames

Frames provide an excellent preventive measure because you can install hanging hardware on the frame instead of directly into the art, and frames make moving and handling safer for the painting. When using hanging hardware, “D” rings should be considered as opposed to eye-hooks. Picture wire can be easily threaded through “D” rings and provides better support for the artwork. A painting should also have a protective backing board to prevent bumps from the back.

Storage

There are various methods for stacking artwork. Generally, stacking paintings horizontally on top of one another should be avoided. If stacking vertically, you should place acid-free cardboard or foam-core boards in between the paintings to avoid adding pressure on the painted surfaces.

Let's just say, hypothetically, that you went through a phase of making six-foot paintings in art school, and you want to convince your parents you got rid of them only to secretly hide them under your bed. One way to properly store such paintings is to remove each canvas from its stretcher, and roll each painting around a padded tube--the larger the diameter the better. Always roll a painting paint-side out! If you skim everything else in this post, please read and remember “paint-side out”! Paint-side-in rolling and folding will compress the paint, and lead to wrinkles and losses in the surface. How to Safely Roll Up a Finished Canvas Painting

​At right is the painting you see above; it was once rolled up, paint in.

When transporting a painting, avoid placing any plastic sheeting or covering directly on the surface of the paint. Even if a painting is fully dried, under some conditions, plastic sheeting can stick to the painting and disfigure the surface. A travel-frame may be considered for safe transportation of your artwork. For more guidelines for travel recommendations, consult this CCI Note on Wrapping a Painting. 

When to see a conservator

As a painting ages, oil paint gets more translucent, varnish will yellow, and paint will probably crack. Some signs of aging are expected, and there’s no need to panic. Even a yellowed varnish, while disfiguring, is not harming the painting. That said, if the yellowing or surface grime is bothering you, go ahead and call a conservator. If you notice that the paint is actively flaking, store the painting flat to avoid losing pieces, and save any flakes you can. A conservator can re-adhere the losses and consolidate the loose layers. If your painting ends up in a flood, you spill something or drop something on it, or if your cat tears a hole through it, we recommend you call a conservator. We’d be happy to help. 

We hope you are enjoying these entries in our series focused on caring for your family heirlooms. This series will continue throughout the summer and cover a variety of items and materials. If you have any comments on the series thus far, including materials you’d like to see covered in future posts, please email us at art-conservation@udel.edu. The previous posts in this series are available on the Department of Art Conservation website here.

You are in our hearts and minds as collectively we face many challenges. We hope you and your loved ones are safe and healthy. When we emerge from this global crisis we must and will rely on art and culture, preserved for today and for future generations, to foster joy, well-being and hope. We encourage you to visit our web site for regular updates on our department of art conservation and news coverage of our treasured students and alumni at home and abroad.