Hi Karla,just a thought - do you know that fresco goes "wacky" for a few days, a week or so, after it is painted? The next day fresco begins to "dry", the colour of the plaster changes from gray to white and since the plaster is under the paint/colour what you see is the colours go crazy (not always) and for a few days it may look really bad. This is called the "drying challenge".
I go through it every time - the one can not get used to it.
But remember in a week or 10 days fresco will pull itself back together, and will look exactly as it did when you set down the brush and said "Its done I like it" on the day of painting. It will be just a shade softer. So wait and do not panic.
In regards to secco - you have to wait a few month before it is safe to retouch fresco with the secco method. Plaster must be completely cured by then.
Take an egg separate white from yolk - you can use ether but not both, unless you plan to make an omelet.
I like whites more, so will brief you on them.
Take egg whites (enough for the project, figure that by practice) put them into the toll glass container and whisk them, will get a cloudy foamy stuff. Put this "stuff" into refrigerator (not a freezer) over night. Next day carefully - do not shake - take the container out of the fridge - the "stuffy stuff" will sink to the bottom, the clear stuff will be on the top. You will need the clear stuff - pour it into the separate container. Mix the clear stuff with vinegar (not the fruity one)
regular vinegar 3% solution, lets say in proportion of 2-3 parts of vinegar to one part of clear stuff (from egg white) - you can adjust the proportion to your preference.
Grind your pigments in this mixture and paint.
Ilia
http://www.truefresco.com/workshop
