In the old days, artwork was replaced after a given number of exposures. However, the perceived number of  maximum exposures varied from company to company. I think for the most part, this practice has been abandoned. We verify film density  after each use when the film is returned to artwork storage. The recommended acceptable density may change based on film supplier but I'm sure your supplier can give you all the information you need.  The other factor is obviously the physical film condition. We would also make new film if the artwork were to be damaged. Hope this helps.

Ed Cosper
Graphic Electronics Inc.



----------
From:  Eltek Ltd. - Process Engineering[SMTP:[log in to unmask]]
Sent:  Tuesday, September 30, 1997 12:34 AM
To:  [log in to unmask]
Subject:  [TECHNET] FAB: Artwotk maintenance

 Hi Technet

    We are interesting what is the procedure of inner layer artwork
maintenance in other P.C.B shops. In other words, is it recommended to
replace the inner layer artworks periodically or per No. of  inner layers
imaged even there is not visually damage in the artworks.

Shabtay Shalev
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]

##############################################################
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
##############################################################

##############################################################
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
##############################################################