# Longitude axis starts at 0 instead of my region bounds when using Mercator projection in PyGMT **URL:** \ **Category:** PyGMT Q&A\ **Created:** [September 27, 2025, 10:38pm UTC](https://forum.generic-mapping-tools.org/t/longitude-axis-starts-at-0-instead-of-my-region-bounds-when-using-mercator-projection-in-pygmt/6214 "2025-09-27T22:38:58Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![yvonnefroehlich](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/yvonnefroehlich/32/5064_2.png) [@yvonnefroehlich](https://forum.generic-mapping-tools.org/u/yvonnefroehlich)\ **Post date:** [September 28, 2025, 8:36pm UTC](https://forum.generic-mapping-tools.org/t/longitude-axis-starts-at-0-instead-of-my-region-bounds-when-using-mercator-projection-in-pygmt/6214/4 "2025-09-28T20:36:37Z")
Hi @muhammetnergizci, **Regarding the font size of the colorbar** Up on GMT 6.5 for mode mode, an automatic scaling of the font size of the colorbar labels based on the width of the colorbar was introduced (please see [#6802](https://github.com/GenericMappingTools/gmt/pull/6802)). In the dev docs there is a note (please see [https://docs.generic-mapping-tools.org/dev/colorbar.html#description](https://docs.generic-mapping-tools.org/dev/colorbar.html#description)). There are several reports and comments on GitHub and the forum (e. g., [GenericMappingTools/pygmt#3041](https://github.com/GenericMappingTools/pygmt/issues/3041) and [Multiple colorbars changes the annotation fontsize](http://forum.generic-mapping-tools.org/t/multiple-colorbars-changes-the-annotation-fontsize/4945)) discussing how to handel this. --- _[View the full topic](https://forum.generic-mapping-tools.org/t/longitude-axis-starts-at-0-instead-of-my-region-bounds-when-using-mercator-projection-in-pygmt/6214)._