Solvents
Solvents are used to wet the nitrocellulose and make the varnish of a suitable consistency to apply,tmly with a brush. Butyl tate and ethyl acetate are the most common solvents and they a:re usually mixed with toluene to stabilise them and regulate their. It is this evaporation which affects the drying time.
Diluents
Diluents help to stabilise the vscosity of the varnish and make the application easier. The most common diluents are three of the alcohols - ethyl, isopropyl and butyl alcohol.
Colour ants
Creme vamishrts contain insol.uble colours mixed with small a.mounts of titanium dioxide. Iron oxide can also be added. PearUsed varnishes get their pearl effect from the addition of brilliant1 reflective, transparent crystals of guanine; these lfe obtained from the skin and scales of small ocean fish such as henmgs. Synthetic pearlising e.g titatium dioxide-coated mica flakes or bismuth oxych:lotide-coated mica. flakes is cheaper, but these p.arti.des tend to be larg-er than those of guanine and so settle out much more quickly.
Qualities
A nail varnish must have several quaHties if it ls to be successful.
1 It mus t have a quick drying time.
2 It must flow smoothly, making it easy to apply evenly with no streaks and little tendency to form air bubbles. These are unavoidable if the product is vigorously shaken or overworked.
3 It mus t dry to a hi.gh gloss.
4 Once dry, the surface must be hard and scrateh-resist, thus
providing a protective coattng to the surface of the nail.
5 The colour should be even in application and cons istent between batches.
6 The product should adhere to the n ail surface wen, making it kmg lasting in wear.
7 It must be flexible when dry with no tendency to ·crack when bent.
8 It must not be allerge nic, or harmful to the nails, or stair1 them with the pigment resins which it contains.
9 The pigment resins must not separate out of the product during storage.
10 Any pearlising should remain in suspen.sion ilnd not settle to the hottom of the bottle. (A tittle settling is inevitable, hence the ball bearings which help to redistribute it.
