Personalized 10 x 13 Tyvek Envelopes Need to send important documents using the strongest envelopes available? Tyvek 10×13 personalized envelopes are what you need. These large business envelopes are made of the durable Tyvek material and are virtually indestructible. Large Tyvek envelopes are custom printed with your return address and are available in open end 10 x 13 size with imprint area of 9.5 x 12.25 inches.
