Specifications include, but are not limited to: Envelopes. All boxes and/or cartons must be clearly marked, showing quantity and type of envelope in each box and/or carton. Envelopes shall be packaged in boxes of 100, 250 or 500 within the carton. Material must be 24 lb. white woven or 28 lb. brown kraft unless otherwise specified. Envelopes shall meet USPS regulations for OCR scan ability. In addition, vendor is asked to provide pricing on a recycled product if available. The New Castle County seal and department address shall be in the upper left-hand corner of the envelope. Exact location must be approved by New Castle County. Business reply and courtesy reply envelopes shall be printed as required by New Castle County. All window envelopes shall be glassine material. Location of windows will vary.