Method for folding absorbent sheet products

A method of stacking a plurality of absorbent sheet products into a stack, the method comprising, for each of the absorbent sheet products of the stack:

• folding an absorbent sheet inwardly only twice parallel to a first axis to define a first inner panel and a second inner panel folded toward each other, said folding comprising folding the absorbent sheet inwardly along a first folding line, substantially parallel to the first axis, to form the first inner panel, and folding the absorbent sheet inwardly along a second folding line, substantially parallel to the first axis and spaced-apart from the first folding line, to form the second inner panel;
• folding the absorbent sheet along a third folding line substantially perpendicular to the first axis to form a first outer panel and a second outer panel, the first and the second outer panels sandwiching the first and the second inner panels therebetween to obtain one of the absorbent sheet products;
• and
• inserting at least a section of at least one of the first and the second outer panels of each one of the absorbent sheet products between the first and the second outer panels of an adjacent one of the absorbent sheet products of the stack.