|Very often documents will be scanned as soon as the recipient gets them, so it's more convenient if there are no staples. However, CA and states that have passed RULONA (including the original poster's state, WA) require that notary certificates be "attached" to the document.|
Generally, staples are considered the minimum for attaching. A more elaborate method that is sometimes used with wills, but unheard of in real estate docs, is to punch holes through all the pages of the notarized doc, run a ribbon through the holes, apply a foil seal over the ends of the ribbon, and use your embosser over the foil.
There has been disagreement in this forum about whether a staple is needed if the notary certificate is on the same page as the signatures of the signers. I say yes, others say no.