Batik is a resist dye technique with hundreds of years’ history in Java. Since I wasn’t with K when someone showed him how to batik, here’s the general gist as I know it:
A natural light-colored cloth is used to make batiks (synthetics or blends won’t work). A rough sketch is made on the cloth as in the first photo. Then you paint wax on top of the areas you do not want to dye. This woman uses a tool sort of like a crude fountain(?) pen to take the dye to the areas she’s drawn. When the paint has absorbed into the cloth it is allowed to dry, then a hot water bath is used to melt off the wax. 
Here’s the finished product. It’s a very thin cloth so it’s beautiful framed with light shining from behind, such as daylight or if indoors then a frame with an embedded lamp. I love bright designs, but this region (Jogyakarta)’s color palette consists of the varying shades and tones of brown.
