John, Boy, have I been round and round with this one before. First of all, Gerber files are by definition nonrasterized files ,i.e."VECTOR". Anyone who is out putting raster files instead of the industry standard 274-X needs to "get with the program". One way or another, this type of ignorance will end up adding non value added cost for someone to the end product. The industry trend does seem to be toward more imbedded ground planes, and less layers. This positive data drawn ground plane has always been the culprit when I have encountered MONSTER FILES,i.e. polygons filled with 2 mil diagonal lines and 2 mil overlap. In almost all cases we have convinced the designer to output the files as. 1. composite, i.e. Positive data signals over Negative data grounds. 2. If drawn grounds must be used, then convert the Polygon fill method to raster instead of vector. Either of these methods can result in as much as a 1000/1 reduction in file size. Yes I said ONE THOUSAND /ONE along with all the time saved all down the line....CAM....Plotting....AOI down load......ElectricalTest and probably some more. We are also spending a substantial amount to upgrade our plotter front end to be able to handle these types of files when they do get in unexpected and HOT without throwing a monkey wrench into production. We have not had an aperture problem with a customer supplied X file In five+ years. The Gerber Format Guide part # 414-100-002 is a very good little book that explains everything you always wanted to know about gerber data but were afraid to ask and can be purchased from Gerber for $35.00 : phone (203) 648-8156. Robert E. Welch Process Specialist Email: [log in to unmask] Modem: 804-239-9120 Fax: 804-237-3048 ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################