Creating a copper patina picture frame

I have an insect display box that I picked up at a garage sale for $1 a while back. I bought it for the lepidopterans that were inside more than for the box itself, which had a frame of cardboard and black book tape that was starting to fray around the edges.

I moved the specimens into a different shadow box (below) and set this one aside while I thought about how to repair it.

Incidentally, I’m either too squeamish or too ethical to be a good lepidopterist or entymologist. The only specimens I’ve ever collected myself are already dead. Here are a few of them (notice some of the bottom two on the right aren’t even dead; they’re just shed exoskeletons):

I used to have a really gorgeous imperial moth that I’d found in the parking garage of my old workplace, but mites got into the case and eventually ate so much of it that it fell apart. I learned later that sticking it in the freezer for a few days would have taking care of the mite infestation. Sigh. Lessons learned too late.

Back to the insect box that started this post: I decided to revamp the box by retaping the frame with copper tape and then giving the tape a patina. I decided on ½-inch tape – that’s how wide the border around the glass is, and it would also be a good width for the edges of a miniature glass greenhouse that I wanted to upgrade. A lot of different lengths were available, from 3 yards to more than 100 yards. I decided on a 55-yard roll to make sure I would have enough for both projects and some future ones as well:

Once it arrived in the mail, I cut off little strips and rubbed them down with various household agents to see what kind of patina they would produce. Among the chemicals likely to produce a patina are acids (found in vinegar, lemon juice and cream of tartar); nitrogen (found in plant food/fertilizer); and salts.

Here is the box after I covered the frame with tape:

Next, I rubbed the surface of the tape with damp steel wool and a little dish soap, making a special effort not to get water under the frame. I then sponged it off with plain water to remove the soap, then dried it with the towel. As a final cleaning step – and the first step in making a patina – I  sprayed ammonia-based glass cleaner on a microfiber cloth and rubbed it on the tape.

I took the lid off the box and set it on a towel. I painted the tape with vinegar-and-fertilizer solution (1 teaspoon granulated Schulz Orchid fertilizer – but any plant food should do –dissolved in 1 tablespoon vinegar). While it was still damp I sprinkled it with kosher salt. I let it dry, then dabbed on just enough vinegar-and-fertilizer solution to dampen the salt.

After it dried again, I wiped off the salt first with a dry rag, then with a damp rag to get the sticky bits off, and then with another dry rag. Some liquid had gotten under the corner of one of the pieces of tape during the patina process, so I had to re-tape and re-patinize a small section.

This is how it looked after airing out for a day:

As more time has passed, a blue-green cast has started to develop:

It’s fun watching the patina deepen from day to day. If it ever gets to a point where I think, “It’s perfect! I don’t want it to develop anymore,”  I’m told that painting it with clear Mod Podge or sealing it with spray acrylic will halt the process.