The machine that these envelopes are printed on needs to be able to grip the envelope, and also requires a margin on all four edges. Also, the envelopes are received from the supplier pre-manufactured (already die-cut and glued into an envelope). For these two reasons, artwork cannot go right to the edge of the envelopes and a white border is required. This white border should be a minimum of 0.5" or 1/2" from each edge.