Attics and Basements and Closets, Oh My! Part 14: Glassware

​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 caring for glassware and was written by rising second-year Objects Fellow, Allison Kelley.

Glass 

Some materials are so ever present in our lives, we may not often consider their specific composition or preservation needs. Glass can be found in everyday objects, such as drinking glasses, windows, and mirrors, as well as in jewelry or fine art pieces that serve a decorative or artistic purpose. Even what we sometimes call “fine crystal” is, in actuality, very clear glass. With materials like glass that we handle every day, it can be useful to step back and examine some of the specific qualities and best-care practices that can be used to ensure the longevity of our cherished belongings.

Glass is formed with a combination of silica and flux that has been heated, worked, and cooled to take its final shape. Various additives can produce different colors or working properties in glass, such as heat-stable cookware or high-grade labware.

​Handling and Moving

The greatest risk to glass is improper handling. While glass is quite stable, it is also rigid and can easily break when too much force is applied. Almost certainly each of us at some point has either broken a glass or watched one fall and shatter in a restaurant. The best way to preserve one’s glass objects is to handle them with care. Always hold an object with both hands and place things gently onto surfaces. When handling stable glass, wearing gloves is not advised. Clean, bare hands will offer greater sensitivity and control when handling a glass object.

When transporting glass objects, a padded container is the safest way to enclose and carry them. If more than one object will be placed in a container, be sure to pad the spaces between the objects with a soft material and try to avoid stacking. 

​Cleaning

The only regular cleaning needed for glass objects displayed out in the open is regular dry dusting. This can be done with your usual dust cloth, keeping in mind careful handling practices. If dry dusting alone does not remove dirt or grime, a cloth dampened with water is a good method for cleaning. Commercial glass cleaners (such as “Windex) can be effective, but the additives in the formulation can leave residues on the surface. When using such products, it is a good idea to follow with a pass of a cloth damp with water to rinse and remove the residues before drying the surface thoroughly.

When cleaning glassware that has been used for food or drink, keep in mind that objects that are placed in a dishwasher will be exposed to more wear and tear than those that are handwashed. Overtime, micro-abrasions on the surface may lead to glassware appearing hazy or opaque. Handwashing with soap, water, and a soft sponge or cloth is a gentler means of cleaning your glassware. When cleaning with soap, be sure to rinse away the soap thoroughly to avoid drying residues.

​Storage and Display

Storing glass objects such as drinking glasses and serving dishes in a cupboard or cabinet is a good way to protect the objects from dust and lower the risk of accidental damage. Objects that are stored in the open should be kept away from the edges of tables or shelves. Generally light exposure is not an issue, but certain formulations of clear glass can change color with long-term exposure becoming “solarized glass.” This tends to occur in older glassworks. For example, a glass piece that contains manganese dioxide, a historical additive used to improve clarity, will take on a purple hue after prolonged light exposure. This is not a particularly common phenomenon, but is something to keep in mind when considering the placement of your glass objects.  

Change Over Time

Glass, generally speaking is stable when left to its own devices. Natural deterioration processes in glass take a very long time, though they can be exacerbated by an acidic or basic environment and fluctuations in humidity. Signs of these processes can include crizzling (small networks of cracks), weeping (formation of droplets on the surface), and spalling (small fragments flaking off of the surface). If you suspect any glassware used for food may be exhibiting these conditions, do not continue to use the object for dining. If you see signs of weeping it can be tempting to simply wipe “the tears” away, but it would be best to leave the surface alone. These conditions cannot be reversed but they can be slowed. To discuss preservation options, consult a conservator. 

Although glass is incredibly fragile, these tips will keep your heirlooms around for years to come. We can all “raise a glass” to that!

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.