The intent of folding large architectural or engineering drawings is to allow the lower portion of the title block to be visible without having to open the entire sheet. This allows a stack of drawings to be filed and then easily identified by the sheet number and drawing title.
Step 1: Fold the drawing in half so that the content is concealed inside the fold.
Step 2: Fold the top leaf back over itself, which will be 1/4 of the original width.
Step 3: Fold the bottom leaf back under the top leaves. You now have an accordion folded sheet that is 1/4 the width of the full sheet and full height.
Step 4: Fold the top half of the sheet under the bottom half.
Step 5: For extra-large drawings, the drawing can be folded in half again.