1) Custom Features - There are tons of features that you can add to your invitations. One of my favourite online stores, Paper-Source, supplies items like coloured printable labels, embossers, rubber stamps, and adorable DIY invitation kits that will make your invitations extra special without that "special" pricetag. I've even found these ever popular boxed invitation kits (comes with boxes, invitations, labels, linen thread, and a real starfish) for about $6.92, which is a steal compared to about $25 from a couture stationer. How amazing would these be for a beach wedding?!
Photo Courtesy of Paper-Source.com
2) Custom Envelopes - At most invitation places, any envelope that's not a white or cream A7 (5"x7"), is considered custom. I've found some great ready-made square envelopes that are about 0.42 each. Even Kate's Paperie offers a 25% discount on some of their envelopes if you purchase 100 or more. Also check with your stationer, who may be selling off over-runs (extras from previous jobs) of perfectly good envelopes for a fraction of the cost.