I think that I've been trying to paint with bold lines and colors too quickly in fresco, causing me to start using 'white' too soon to blend form. And any pigment with red in it ends up becoming too harsh in a few days, whether it's a sienna color or red earth or cadmiums etc. What looks like a good reddish stroke or proper shading ends up appearing too brash and hard when the painting starts to 'dry.' And if I've used any lime-white tints, those fade , like you say, leaving the surrounding pure color area like an island of color, out-of-whack with the white-blended parts.
You say to use lime-white putty "in the beginning" and also " at the end of the day" ? I'm not sure I understand.
I've tried every combination of white: lime putty by itself...putty and bianco sangiovani...putty and titanium white mixed...titanium white alone...putty and fine marble dust.... But still can't control the final appearance. Plain lime-putty sticks the best and I wish I could figure out how to just use that, and no other whitening agent. It just feels like pure fresco when only lime-putty is used.
I received the FrescoShop bucket of lime putty today, and am going to do some small test swatches with it using different grades of sand and proportions. Why do you use less sand for the intonaco layer ( 5:8 lime/sand ) than for the undercoats which are 1:2 ? For smoother surface or better adhesion?