Should the words on the couplet banner go from left to right or from right to left?

According to the traditional writing method, horizontal couplets should be written from right to left, and the corresponding couplets should be posted on the right; Now, due to the change of study, reading is typesetting, reading from left to right. Therefore, the pasting method of the upper and lower couplets is not very strict, and the horizontal batch is also written differently. But no matter how you write, just remember one thing, that is, write horizontally from left to right, with the couplets on the left, and vice versa. It's the only way now.