Offset printing is the most affordable option. This is where the paper is pressed against a metal plate to create letters or designs. Thermography or photo lettering may be a little more expensive. This process fuses ink and a printing powder to create a raised lettering style more classic to invitations. The result is a lettering that is slightly raised from the page and embossed on the backside.
Font styles are another choice, when choosing a front pick one that is easy to read.
Pick a font that lends itself nicely to your invitation style. Print colors again offer many choices. The standard classic is black, and many stationery companies do not charge additional for black inks. Color choices are offered in a rainbow of colors. You may also consider foil imprinting or pearlized print for an up charge.