STANDARD SIZES AND WEIGHTS: FIRST Class- up to 4.25 X 6 - the weight for this sized card must be a minimum of 7 PT PRSTD Standard - up to 4.25 X 6 - the weight for this sized card must be a minimum of 7 PT LARGER SIZED CARDS: PRSTD Standard (only) from 4.25 X 6 through 6.125 X 11.5 the weight must be a minimum of 9 PT (NOTE THAT 80# GLOSS COVER DOES NOT QUALIFY AS A MINIMUM OF 9 PT, 80# MATTE COVER MAY QUALIFY BUT YOU MUST DOUBLE CHECK THE WEIGHT OF THESE STOCKS AS THIS CAN VARY FROM MILL TO MILL). DO NOT TRY TO MAIL ANYTHING SMALLER THAN 3.5 X 5.5 as these will not mail. Often times it is less costly to send a post card (up 4.25 X 6) First Class Mail/Post Card Rate as opposed to sending it PRSTD Standard. You do not want to send an oversized post card (above 4.25 X 6) First Class as it will be more expensive than PRSTD Standard. For best postal rates: address along the long side of the piece. If you address along the shorter side then you will pay a surcharge as high as 10-12 cents per piece. ASPECT RATIOS Your project aspect ratio is very important (i.e. Aspect Ratio is length/width). For the best postal rate the aspect ratios should NEVER be between 1 and 1.3 but should always be between 1.3 and 2.5. To make this easier to understand: if the piece looks like a rectangle you are probably okay, if it looks like a square you are in trouble. FLATS Anything larger than 6.125 or 11.5 in one dimension will ship as a FLAT instead of at PRSTD Standard / bulk rate. FOR FLATS -- THE ABOVE WEIGHTS AND ASPECT RATIOS DO NOT MATTER BECAUSE YOU ARE ALREADY PAYING THE HIGHER (PREMIUM) POSTAL RATE. REFLECTANCE Using colors, screens and/or patterns beneath the address area of a mail piece is not recommended. White is the safest and easiest of all colors to use in the address area, all other colors and screens are subject to scrutiny from the post office. Reflectivity/reflectance must be above .5 according to USPS standards. The darker the area being addressed/inkjetted - the lower the reflectance. A patterned background is a bad idea as well since a barcode will be printed on top of a pattern and the pattern will render the bar code impossible to read with automation. The post office may bounce the entire project if there is a pattern behind the address portion of the inkjet. Your addressing window size should be 4 X 2.5. The addressing box should be a half inch from the right side and 5/8 in. from the bottom of the fold for best mailing.