Liquidambar Leaf Contact Prints on Silk

For some years, I have pored over tantalising online images of fabric eco printed with Liquidambar leaves. I've never found any growing locally, and believe me, I've looked. Hard to miss, with those simple, five pointed leaf shapes and rich red autumn colours, a Liquidambar would stand out among the yellow and brown Welsh woodlands. The tree is an American native, also known as a sweetgum. In its natural habitat it can grow 50m tall. 
When I planted the one in this picture, my companion, Elinor Gotland, feared her days of sunbathing on the back lawn would soon be over.
"You want your head read, Beaut. That tree will overshadow the neighbourhood, never mind the garden."
"Chill your beans, Elinor. This variety is called Gum Ball and it won't grow more than a couple of metres high."
She gave me a sceptical look.
"That's what you said about the clematis that took over the back of the house. What's that stuff you're putting down the planting hole? Don't go feeding it too much manure."
"It's ericaceous soil. I'm digging it in to acidify our alkaline clay earth. Acid conditions will help the leaves develop a good autumn colour."
"One little bag of the ericaceous stuff will be about as much use as lace knickers on a frosty night. You'll never shift the pH of that whole border."
I stopped to lean on my spade.
"You start saving all your used tea bags and we'll have a cubic metre of acid mulch by Christmas."

The Gum Ball survived a wet and bitter cold winter and this autumn, the display of leaf colour has been a tribute to Elinor's capacity for tea drinking. I have been picking a few leaves for contact printing by rolling them up on plant dyed cloth with an iron blanket and steaming (details of method here) and found my home grown leaves do make decent iron blanket prints, clearly outlined and often filled with their own dye colour in a pink, brown or purple shade. This photo shows a couple of their five pointed leaf shapes on a silk scarf previously dyed a pale yellowy green in an ivy leaf dye bath.
Where they really stand out dramatically from the other leaves is shown in the very dark prints they leave behind on the iron blanket. As deep as oak leaves, so perhaps Liquidambar contains a lot of tannin.

I decided to have a closer look at Liquidambar leaves by dipping them in dilute iron solution and printing with them by steaming in a roll of plain white silk. At the same time, I could try to find out how much their visible autumn colour predicted their dye print colour and compare their prints with sycamore leaves, which you can see lined up on the lower row on this alum mordanted silk scarf.

The iron dip enabled both kinds of leaf to print silhouettes with patterns of veins. After washing and ironing, I'd say the iron prints look more delicate from green leaves, deeper from leaves that have changed from green to yellow and deepest from the red ones.

Of course, the darkness of the iron does obscure any dye colours. I think the Liquidambar leaves which had developed red autumn colours did leave a pinker cast within the shades of grey. I've often noticed people talking about spraying on vinegar before ecoprinting fabric. Alright, yes, I do know vinegar is not a mordant, but I did think maybe its acidity might modify and enhance red anthocyanin dye from the leaves. Here are two scarves after printing and allowing a couple of weeks to cure before washing and ironing. The one on the right was soaked in white vinegar before printing, the one on the left was just soaked in plain water.

I'd say the vinegar increased the yellow halo, which I assume comes from leaf dye tracking through the damp silk during steaming. It does look as though vinegar did slightly deepen the pinkish brown colour from the red Liquidambar leaves. All in all, not fabulous results, I think I'll overdye these scarves with some flower prints next summer. Next autumn, I'll try a similar experiment using a iron blanket instead of dipping the leaves in iron solution. As Elinor Gotland pointed out, some of the old cotton sheet I've cut up to make iron blankets this autumn looks more attractive than the silk I'd hoped to print.