本格
ほんかく · honkaku · JLPT N1 · noun
full-scale
本 — tree 木 + mark at base
本 is a pictograph of a tree (木) with a stroke at its base, marking the roots. From this 'root' meaning it extended to 'origin,' 'source,' and 'foundation.' In modern usage it also serves as a measure word for bound objects like books.
格 — wood 木 + 各 (each, phonetic)
格 is a semantic-phonetic compound: 木 (wood) gives the meaning, originally referring to a wooden frame, lattice, or crossbar, while 各 supplies the sound. From 'frame/grid' the meaning extended to 'pattern, standard, style' and the modern senses of 'square (in a grid)' and 'character/disposition'.