Thank you for replying so promptly.
I will try what you suggested today.
With the white cat ( he is visible on the website) i can only try to sand him as there are small spots everywhere or redo him from scratch ( no pun intended) at the worst.
But what do you call "pastino"?
I work with plaster of Paris (special fibrous quality for staff), skin glue and pigments. I sometimes add a bit of linseed oil.
The new little blue horse I made just doesn't want his holes filled: the fill mixture keeps on drying to chalk although i have wetted the horse beforehand.
I thought i had solved the problem thanks to Ed ( he also posts on this forum). Ed is not available at the moment and I am getting anxious again!
It make me think twice before starting on the scagliola project i mentionned in my "off the forum" e-mail to you. What if the fills keep on drying to chalk again?

This must sound incredibly silly!

Here are a few of the links I have used to try to learn about scagliola. The italian Massinelli book seems to be "the thing", but it is very difficult to get, I believe and, being rare, probably expensive.

1/Most of the stuff is, alas, in Italian. With my French and my Spanish I try to understand.
The stuff in English is interesting for beginners.

http://www.plasterarc.net/
http://www.plasterarc.net/essay/index.html

2/Very interesting, although old fashioned at times. But perhaps closer to crafts people and the "real" thing.

http://freepages.history.rootsweb.com/~quarries/marble_workers_manual/mwh-p4_sect1_2.html#imitation_m

3/More technical, it is restoration, but many parts confirmed what i had found on the other sites.

http://www.chemie.uni-hamburg.de/ac/AKs/Dannecker/enviart/second.html

4/ I haven't read it. But have come across the ref.of this book on a few web sites.

http://www.massinelli.com/
http://www.massinelli.com/Scagliola.html

Hope i haven't been too long

Marmorino
http://perso.wanadoo.fr/arba7/pandora/index.html