diff --git a/fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_wizard.py b/fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_wizard.py
index b513d54d..b1e68727 100644
--- a/fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_wizard.py
+++ b/fusion_plating/fusion_plating_configurator/wizard/fp_direct_order_wizard.py
@@ -716,6 +716,12 @@ class FpDirectOrderWizard(models.Model):
                 'x_fc_serial_id': line.serial_id.id or False,
                 'x_fc_job_number': line.job_number or False,
                 'x_fc_thickness_range': line.thickness_range or False,
+                # Express Orders per-line flags (2026-05-26) — carry to
+                # the SO line so the override-application helper can read
+                # them at job creation time.
+                'x_fc_customer_line_ref': line.customer_line_ref or False,
+                'x_fc_masking_enabled': line.masking_enabled,
+                'x_fc_bake_instructions': line.bake_instructions or False,
                 # Sub 9 — explicit tax override from the wizard line.
                 # When blank, Odoo will compute taxes from the product
                 # defaults at SO-line save time (the standard behaviour).
@@ -762,6 +768,28 @@ class FpDirectOrderWizard(models.Model):
                 continue
             if line.thickness_range and not part.x_fc_default_thickness_range:
                 part.x_fc_default_thickness_range = line.thickness_range
+
+        # Express Orders part-default write-back (2026-05-26).
+        # Always-on (no push_to_defaults check): the spec says type-once,
+        # saves to part. Empty cells DON'T clobber existing defaults
+        # (otherwise an empty bake cell would erase a part's bake default
+        # — bad UX). Masking is a Boolean so always written.
+        for line in self.line_ids:
+            if line.is_one_off:
+                continue
+            part = resolved_parts.get(line.id) or line.part_catalog_id
+            if not part:
+                continue
+            wb_vals = {}
+            if line.line_description and not part.default_specification_text:
+                wb_vals['default_specification_text'] = line.line_description
+            if line.bake_instructions and not part.default_bake_instructions:
+                wb_vals['default_bake_instructions'] = line.bake_instructions
+            # Masking is always written (Boolean has no notion of empty).
+            if part.default_masking_enabled != line.masking_enabled:
+                wb_vals['default_masking_enabled'] = line.masking_enabled
+            if wb_vals:
+                part.sudo().write(wb_vals)
         so.message_post(body=_(
             'Quotation created from PO %s with %d line(s). '
             'Review and confirm manually when ready.'