Preserving St Clair Fossils with Decoupage

[hitekmastr]

I have been trying to find a reasonable solution for preserving St. Clair fossils, which are mineralized in white, yellow and orange colors.  Cleaning with water dissolves the colors.  Coating with most types of glue will also remove the color, turning white fossils to black!  I experimented this week with decoupage, which seems to preserve the white mineralized fossils without changing them, and gives the specimen a glossy sheen.  I am interested in this because the colors of St. Clair fossils are fairly robust, but can flake off over time, and may suffer from oxidation.  My reason for posting is to ask if anyone has good reasons to NOT use decoupage to preserve and seal St. Clair fossil specimens?  Here is a photo one the first one I tried, which is a small fragment - note the glossy sheen, and also how the color and detail was preserved.  Decoupage looks milky when applied but dries clear.  I want to verify that this is a good approach before trying this on larger speciments, some of which are 1 to 2 feet in size.

[Uncle Siphuncle]

I've used artist's spray fixative with good results.

[caldigger]

44 minutes ago, Uncle Siphuncle said:

I've used artist's spray fixative with good results.

And it comes in a matte finish, so you can avoid the sheen if desired.

Look for charcoal/ pastel fixative.

I would be afraid because Decoupage is brushed on, you may run the risk of wipping some of the mineralization off the surface of the plate. 

[Ptychodus04]

What is decoupage made of? Depending on this answer, you could experience significant yellowing over long periods of time, effectively ruining the specimens.

 

Modern conservation materials are specifically chosen for their long term stability.

[Ludwigia]

On 7.1.2019 at 6:02 AM, Uncle Siphuncle said:

I've used artist's spray fixative with good results.

Me too. Never tried decoupage. Don't even know what it is, so I guess I'll have to google it now.