Combine all the seeds in a large bowl, Add the water and salt and let the mixture sit for a few minutes, until all the water is absorbed.
Dehydrating: pour the batter onto a lined tray and spread it as thinly and as evenly as possible. A spatula is great for this, but if you don’t have one, just wet your hands and kind of pat it down. Try not to leave any holes. Dehydrate at 115ºF (46ºC) for about an hour and then score the cracker into desired shapes. Put the tray back into the dehydrator and keep dehydrating until the cracker is completely dry.
Baking: pour the batter onto a baking sheet lined with parchment paper and spread it as thinly and as evenly as possible. Bake at 300ºF (150ºC) for about 20 minutes and then cut the cracker into desired shapes with a knife. Once scored, carefully flip the cracker.** Peel the parchment paper off the back and then bake for additional 20 minutes or until the edges are golden brown. Let cool completely, then break the crackers along their scored lines.
Store leftover crackers in an airtight container at a room temperature for up to 2 weeks.
For longer term storage, freeze in an airtight container for up to 1 month.
*For raw crackers, use raw unhulled sesame seeds. Unhulled sesame seeds are very crunchy, almost hard, and taste slightly bitter. Toasted hulled sesame seeds (not raw), on the other hand, have a nutty, clean flavor.
**The easiest way to flip the cracker is to slide the parchment paper from the baking sheet onto a big cutting board. Then cover the cutting board with the baking sheet and flip the cutting board over.