Torma's a huge subject.
Each tradition or lineage has it's own specific shapes, colors, ornaments, etc.
Some tormas are seen to represent the deity or deities and mandala, some are seen to represent offerings of food, or the five senses, or other things. Some are seen as weapons.
Some are offered to the jnanasattvas, some to the "gek," some to jungpos and local deities, etc.
Yudron, many of the Sarma practices don't offer a preliminary Kartor for the "host"--and some don't offer "Gektor," per se---though many have a "ngontor," or preliminary torma. It's all specific to a given sadhana. Also, the "mentor" is, to the best of my knowledge, a Nyingma thing--though I may be wrong. The only times I've used Mentor is when performing practices that come from Nyingma lineages.
Greg's diagram of a "Baling" is Karma Kagyu tradition--balings are used for offering to protectors, and also sometimes are used on the Tentors/Phuktors, or deity tormas, as well, depending on the practice being done. Even in the Karma Kagyu tradition, there are two main subtraditions of torma making--the Tsurphu and Palpung methods.
Some folks are working on a movie about Tormas, should be pretty great when it's done.
My Lama teaches tsampa as the basis for tsok tormas, but we use regular barley flour for most other tormas. Sometimes oatmeal can be used, too. We use butter for gyens, but chuppens from India often use Dhalda, which is shortening, mixed with paraffin, for gyens. Also, in Sikkim they cook rice and mash it up to make tormas. So, the main ingredients can vary.
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