Regarding miniature portraits:
Can you give us some additional information? Are these portraits
on ivory, porcelain, canvas, wood? Are they framed--and with
glass?
They do not necessarily need to be wrapped in acid-free tissue.
I have seen portraits on ivory laid flat in drawers or hung on
walls. I would suggest drawers if the paintings are on ivory as
ivory tends to respond dramatically to humidity changes. Drawers
have the added feature of creating one more micro-climate--slowing
down the affects of any climatic changes in the store room from
reaching the miniatures. Also, some of these portraits can be
light sensitive--another plus for drawers.
Hope this helps.
John Handley