If you are printing the copies for the recipients of those forms (or for your own records) then yes you can use regular copy paper.
If you will NOT efile the forms needed to go to SSA (W-2 & W-3) then those can also be on regular paper.
If you will NOT efile the forms needed to go to the IRS (1099 copy A & 1096) then those must be on the IRS red forms which you can get mailed to you for free : https://www.irs.gov/businesses/online-ordering-for-information-returns-and-employer-returns
(Or buy at the office supply store for a fee)
The RED forms must not be stapled or folded since they must be in scannable condition.
