The logo design, especially the font (called "Westinghouse" or "Anklepants" (due to a similar typeface) by some people), was originally introduced when then-owner Westinghouse Broadcasting (Group W) introduced its design language in 1963.
In 1995, CBS entered into an agreement with the Westinghouse Broadcasting Company, which owned WJZ-TV and four other stations. This resulted in WJZ-TV switching from ABC to CBS, sending that ABC affiliation to WMAR-TV channel 2, who lost its NBC affiliation back to WBAL-TV channel 11.
4 years since the switch to CBS, WJZ-TV modified and softened their Westinghouse typeface to replace the original logo. The old one was still kept as the secondary logo and is currently only seen in their headquarters.
1999–2002 (primary)/2002–2018 (secondary)
This variant was still used on the "Manic Monday" segment intro until it was replaced with the 2017 logo in 2018.