Measure the width and height of the letter or document
Add extra margin for overlap and folding (typically 1–2 cm)
Choose paper type and size (printer paper, cardstock, or wrapping paper)
Cut paper to the required dimensions
Place the letter centered on the paper
Fold one side over the letter to cover it
Fold the opposite side over to overlap the first fold
Fold the top and bottom flaps over the letter
Trim any excess paper if needed
Apply glue or double-sided tape on the overlap areas
Press firmly and let it set
Optionally add a closure flap or sticker seal to secure the cover
Insert the letter and confirm it fits snugly and stays protected