The ones I've presented so far are only 8x10. Today I am going to do some salt prints at 10x14. I will do much larger once I get my new print frames built. The actuality of paper costs is the larger the roll, the less expensive it becomes. I want to do 18 x 24's in all my processes, I just need larger contact print frames which are prohibitively expensive.
To do the botanicals, no issue with print frames, you just need large pieces of tempered glass and a wide outdoor space to work in with good, direct sunlight. I generally prepare four to six papers so I can take advantage of the direct, overhead sun for two to three hours. Once exposed, I can process them all at the same time, or one at a time, at least for the preliminary step to get a good, cyanotype image. Once they are all dried overnight, then I can have more fun with them as a good spritz of vinegar instantly revives the cyanotype chemistry. With all these processes, metal trays or tongs are a huge no-no. Plastic, glass or bamboo are the better choices.