Blank sheet, cushioning material, and packing method

A blank sheet that is capable of being folded to assemble a cushioning material comprising:

• in an assembled state where the blank sheet is assembled,
• a base having a first main surface and a second main surface opposite to the first main surface and having a first end and a second end opposite to the first end;
• a first side wall extending from the first end in a first direction from the first main surface toward the second main surface;
• a second side wall extending from the second end in the first direction;
• at least one first adjuster being a part of the base and being deformable between a first state and a second state, wherein the first state is unbent at a first position away from the first side wall in a third direction from the first end toward the second end, and the second state is bent in the first direction at the first position;
• and
• at least one first support supporting the at least one first adjuster in the second state, wherein
• in the first state, a first space is defined, on the first main surface, between the first side wall and the second side wall, and
• in the second state, a second space is defined, on the first main surface, between the at least one first adjuster and the second side wall, and the second space is smaller than the first space.