The natural dyes add shine to the colors and have an advantage of getting wide variety of colours and tones and shades (except white and pink). The colors have better lustre and are transparent as compared to the synthetic ones. Probably the titanium dioxide reduces the lustre in synthetic dyes. It is also possible that the natural dyes mix with lacquer much better than the synthetic dyes.
His experiments in this regard resulted in a wide variety of tree-based dyes. Since they were lead free, Padmavati Associates made considerable profit in the market and got orders from international clients.
The dyes, whether natural or synthetic, are generally available in powder form. Lacquer pellets are heated slowly in an open oven while the colours and titanium dioxide in powder form are applied to the fluid in small quantity at regular intervals. The thick fluid of the lacquer is stretched and twisted on the oven for proper distribution of the colour with lacquer. This process of applying colours over the oven is continued till the lacquer turns into required shade.
This coloured lacquer is stretched, cooled and cut into small sticks. These sticks are applied to the toys and artifacts while turning on lathe. Dried leaves of `mogali’ (Morinda citrifolia) are used for finishing and polishing.
Raju further experimented with tree and plant based dyes, which did not require any binding material such as titanium dioxide and most when tested, were lead-free. Those that showed signs of toxicity developed micro-toxins only if they were preserved in the form of slurry or liquid for a long duration. Raju developed a technique to preserve them in the form of cakes, thus avoiding development of micro-toxins. The natural dyes add shine to the colours and are available in wide variety of colours, hues, tones and shades (except white and pink). The colours have better lustre and are transparent as compared to the synthetic ones.