This is our thirty-first LABAC cut glass book. The advertisements project work began in 2002 and soon accumulated more than 4,500 pages of cut glass advertising material. The four Cut Glass Advertisements books published during 2003 were soon recognized by the cut glass research community as valuable tools supporting pattern identification, cut glass research and catalog/pattern dating. Although coverage was high, occasionally someone later saw a cut glass advertisement or article that had not been reprinted. During late 2003, LABAC began accumulating additional advertisements not reprinted in the earlier Ad Books. That effort continued for fourteen years. As LABAC activities declined, a decision was made to scan the fresh advertising material for eventual posting to the ACGA website. Price Chandler accomplished the advertisement scanning and quite a lot of scan file cleanup. After partial assembly of this material into company-sequenced pages, LABAC activities were suspended. During early 2017, it was decided to complete assembly and publish the accumulated advertisements in book form. Rob and Val Smith cleaned up more ads, then produced the sequence of page images subsequently used by the revived LABAC group to publish Cut Glass Advertisement Books Five and Six.Each chapter contains advertisements related to a single cut glass promotional entity. We have chosen to begin AD5 and AD6 page sequencing with numbers that continue the page numbers after those in the corresponding company chapters of AD1-AD4. Ads are reprinted full-sized, with two or more smaller ads for a company shown on a single page. The origin of each ad is indicated, citing periodical name, date and page number. Ads with missing or incomplete citation data were included, in case these may be useful to researchers. This book includes cut-glass-related advertisements for ninety companies, including forty-five firms that did not appear in the earlier advertisement reprint books.