Thank you for your opinion . What about walnut ink I guess just because of the light brown color in the caption and frame sheet . And as I wrote it the same color . Burning does not exist in one place . Maybe ordinary ink or no ink .
" Hard to say .
The first time after purchase really wanted to open the box and see , can on the reverse side there are some inscriptions , but fear that the sheet crumble in the incompetent hands of my curiosity overpowered . Left as is . And yet . Mounting frame ( only three survived ) of copper. On the flip side there is a sticker , or rather was . She was not frustrated , but faded almost completely. Individual traces of inscription in the box remained . Add a photo .