I need ideas for shelves on a wall with a soffit

If the soffit is there to hide a/c tubing or other utilities, it can't be moved cheaply but you still could have a whole library of shelving. Measure carefully to see what height you have, paying attention to any quarter round or other bottom trim you have to deal with. I'm going to use 7 ft. or 84" as an example. It's worth checking at recycled materials stores, Home Depot, Walmart and and even online for already built bookcases at or near the right height. Even if you have to put them together out of boxes, check the prices against buying lumber of 14 vertical feet and maybe 18 linear feet (shelves) for each bookcase. 5 1/2 or 6 feet bookcases would also fit. You just add the ends to go up to the soffit. Color the cases however you want, but also paint or use wood planks to cover the soffit. You should end up with shelving up to the ceiling with the soffit appearing to be part of built in bookcases. (You might like to add narrow wood trim to cover any small gaps between bookcases.). I'll leave building original bookcases to others. I hope you think big. Best wishes 😇 .