paste is a nice solution. However, the OP didn't state whether the files had the same number of lines or not, but did mention printing from both files. In the case of files with a different number of lines, paste continues printing up to the end of the larger file--and corresponding blanks for the smaller--after the smaller file's exhausted. This exception does not meet the OP's specs of printing from both files on each line. However, it may be the case the the files have the same number of lines; if so, this simply isn't an issue.