What is the process involved in the FOIL method?

The FOIL method is a technique used in hair coloring, particularly for highlighting. This process involves weaving strands of hair and then encasing them in aluminum foil or similar material. The foils help to isolate the selected hair strands from the rest of the hair, allowing for precise application of lightening or coloring agents. This method not only provides a controlled way to achieve highlights but also helps in preventing the color from bleeding onto other hair strands.

The other choices do not accurately represent the FOIL method. Applying color to all hair strands suggests a more uniform approach rather than the selective highlighting that the FOIL technique offers. Using heat to change hair texture refers to processes like perming or straightening and does not involve coloring hair. Direct application of a lighter product without sectioning lacks the precision required for highlights, which is a key element of the FOIL method where controlled isolation of strands is essential for achieving the desired results.