diff --git a/PyTeX/format/simple_tex_formatter.py b/PyTeX/format/simple_tex_formatter.py
index 6958764..625cb2c 100644
--- a/PyTeX/format/simple_tex_formatter.py
+++ b/PyTeX/format/simple_tex_formatter.py
@@ -2,6 +2,7 @@ from .formatting_config import FormattingConfig
 from .tex_formatter import TexFormatter
 from pathlib import Path
 from typing import Optional, List, Tuple, Dict
+from .enums import TeXFlavour
 
 
 class SimpleTeXFormatter(TexFormatter):
@@ -26,3 +27,10 @@ class SimpleTeXFormatter(TexFormatter):
     @property
     def output_files(self) -> List[str]:
         return [self.input_file.with_suffix('').name]
+
+    def _post_process_line(self, line: str) -> str:
+        if self.config.tex_flavour == TeXFlavour.LaTeX2e:
+            raw = line.rstrip(' %\n')
+            return '' if raw == '' else raw + '%'
+        else:
+            return line.rstrip()
diff --git a/PyTeX/format/tex_formatter.py b/PyTeX/format/tex_formatter.py
index 4980ce6..3777389 100644
--- a/PyTeX/format/tex_formatter.py
+++ b/PyTeX/format/tex_formatter.py
@@ -105,8 +105,15 @@ class TexFormatter(PyTeXFormatter, ABC):
             self.line_stream.pop_line()
             self.line_stream.push_lines(res)
 
-    def _shipout_line(self):
-        line = self.line_stream.pop_line().rstrip()
+    def _post_process_line(self, line: str) -> str:
+        """
+        Can strip line or add comment symbols etc.
+        :param line: Line, potentially with trailing newline
+        :return: Line without newline symbol
+        """
+        return line.rstrip()
+
+    def _shipout_line(self, line):
         self.write_line(line + '\n')
 
     def write_line(self, line: str):
@@ -135,7 +142,9 @@ class TexFormatter(PyTeXFormatter, ABC):
                         self._handle_macro(macro)
                         recent_replacement = True
                         break
-            self._shipout_line()
+            self._shipout_line(self._post_process_line(
+                self.line_stream.pop_line()
+            ))
 
     def format(self, build_dir: Path, overwrite: bool = False) -> List[Tuple[str, FormattingConfig]]:
         self.open_output_stream(build_dir)