diff --git a/geminidr/core/primitives_spect.py b/geminidr/core/primitives_spect.py
index eab1065ea..7d7990f6b 100644
--- a/geminidr/core/primitives_spect.py
+++ b/geminidr/core/primitives_spect.py
@@ -806,7 +806,7 @@ def _get_fit1d_input_data(ext, exptime, spec_table):
                 uiparams = UIParameters(config)
                 visualizer = fit1d.Fit1DVisualizer({"x": all_waves, "y": all_zpt, "weights": all_weights},
                                                    fitting_parameters=all_fp_init,
-                                                   tab_name_fmt="CCD {}",
+                                                   tab_name_fmt=lambda i: f"CCD {i+1}",
                                                    xlabel=f'Wavelength ({xunits})',
                                                    ylabel=f'Sensitivity ({yunits})',
                                                    domains=all_domains,
@@ -1354,7 +1354,7 @@ def determineWavelengthSolution(self, adinputs=None, **params):
                 visualizer = WavelengthSolutionVisualizer(
                     reconstruct_points, all_fp_init,
                     modal_message="Re-extracting 1D spectra",
-                    tab_name_fmt="Slit {}",
+                    tab_name_fmt=lambda i: f"Slit {i+1}",
                     xlabel="Fitted wavelength (nm)", ylabel="Non-linear component (nm)",
                     domains=domains,
                     title="Wavelength Solution",
@@ -2987,7 +2987,7 @@ def recalc_fn(ad: AstroData, ui_parms: UIParameters):
                 ui_params = UIParameters(config, reinit_params=reinit_params, extras=reinit_extras)
                 visualizer = fit1d.Fit1DVisualizer(lambda ui_params: recalc_fn(ad, ui_params),
                                                    fitting_parameters=[fit1d_params]*count,
-                                                   tab_name_fmt="Slit {}",
+                                                   tab_name_fmt=lambda i: f"Slit {i+1}",
                                                    xlabel='Row',
                                                    ylabel='Signal',
                                                    domains=all_shapes,
diff --git a/geminidr/gmos/primitives_gmos_longslit.py b/geminidr/gmos/primitives_gmos_longslit.py
index 45f332c85..385c2d5ec 100644
--- a/geminidr/gmos/primitives_gmos_longslit.py
+++ b/geminidr/gmos/primitives_gmos_longslit.py
@@ -793,7 +793,7 @@ def reconstruct_points(ui_params=None):
                 extras = {"row": RangeField("Row of data to operate on", int, int(nrows/2), min=1, max=nrows)}
                 uiparams = UIParameters(config, reinit_params=reinit_params, extras=extras)
                 visualizer = fit1d.Fit1DVisualizer(reconstruct_points, all_fp_init,
-                                                   tab_name_fmt="CCD {}",
+                                                   tab_name_fmt=lambda i: f"CCD {i+1}",
                                                    xlabel='x (pixels)', ylabel='counts',
                                                    domains=all_domains,
                                                    title="Normalize Flat",
diff --git a/geminidr/interactive/fit/fit1d.py b/geminidr/interactive/fit/fit1d.py
index c70b45b55..ef687b069 100644
--- a/geminidr/interactive/fit/fit1d.py
+++ b/geminidr/interactive/fit/fit1d.py
@@ -1547,7 +1547,7 @@ def __init__(
         fitting_parameters,
         modal_message=None,
         modal_button_label=None,
-        tab_name_fmt="{}",
+        tab_name_fmt=None,
         xlabel="x",
         ylabel="y",
         domains=None,
@@ -1590,8 +1590,8 @@ def __init__(
             If set and if modal_message was set, this will be used for the
             label on the recalculate button.  It is not required.
 
-        tab_name_fmt : str
-            Format string for naming the tabs
+        tab_name_fmt : callable
+            Turns ext.id into a title for the tab name
 
         xlabel : str
             String label for X axis
@@ -1770,6 +1770,9 @@ def kickoff_modal(attr, old, new):
 
         elif turbo_tabs:
             self.turbo = TabsTurboInjector(self.tabs)
+            
+        if tab_name_fmt is None:
+            tab_name_fmt = lambda i: f"Extension {i+1}"
 
         for i in range(self.nfits):
             extra_masks = {}
@@ -1799,12 +1802,12 @@ def kickoff_modal(attr, old, new):
 
             if turbo_tabs:
                 self.turbo.add_tab(
-                    tui.component, title=tab_name_fmt.format(i + 1)
+                    tui.component, title=str(tab_name_fmt(i))
                 )
 
             else:
                 tab = bm.TabPanel(
-                    child=tui.component, title=tab_name_fmt.format(i + 1)
+                    child=tui.component, title=str(tab_name_fmt(i))
                 )
 
                 self.tabs.tabs.append(tab)
diff --git a/geminidr/interactive/fit/tracing.py b/geminidr/interactive/fit/tracing.py
index d6e990f5b..56085377d 100644
--- a/geminidr/interactive/fit/tracing.py
+++ b/geminidr/interactive/fit/tracing.py
@@ -65,7 +65,7 @@ def interactive_trace_apertures(ext, fit1d_params, ui_params: UIParameters):
         fitting_parameters=fit_par_list,
         help_text=help_text,
         primitive_name="traceApertures",
-        tab_name_fmt="Aperture {}",
+        tab_name_fmt=lambda i: f"Aperture {i+1}",
         title="Interactive Trace Apertures",
         xlabel=xlabel,
         ylabel=ylabel,