Pith paper is a spongy, cellular material sliced from the stems of a specific Asian shrub rather than pressed from wood pulp or rags. It absorbs heavy gouache pigment deeply, giving flowers and figures a distinctive velvety dimension. Because this organic medium is exceptionally fragile, surviving nineteenth-century examples require secure framing behind glass to prevent crumbling.

How do I tell gouache from watercolour?

Gouache contains added chalk or white pigment that makes the paint completely opaque, allowing light colours to sit visibly over dark washes. Watercolour remains transparent, letting the white of the paper shine through every layer. Examining the surface under magnification reveals the dense, matte pigment build-up characteristic of body colour rather than translucent staining.

Can I hang these paintings in direct light?

Direct sunlight causes fugitive pigments in antique water-based paints to fade and degrades paper supports over time. Displaying them on interior walls away from windows ensures the colours remain stable. Fitting frames with UV-filtering glass provides an extra layer of protection against environmental light damage in domestic settings.