private void ProcessOverprintLogic(PdfPage page)
{
    // Ensure the backup dictionary exists for this page
    if (!_objectStateBackup.ContainsKey(page.Handle))
        _objectStateBackup[page.Handle] = new Dictionary<IntPtr, BlendTypes>();

    var pageBackup = _objectStateBackup[page.Handle];

    if (_enableOverprint)
    {
        // --- ENABLE SIMULATION ---
        foreach (PdfPageObject pageObj in page.PageObjects)
        {
            if (pageObj.StrokeOverprint || pageObj.FillOverprint)
            {
                // Save original state if not already saved
                if (!pageBackup.ContainsKey(pageObj.Handle))
                {
                    pageBackup[pageObj.Handle] = pageObj.BlendMode;
                }

                // Apply simulation
                pageObj.BlendMode = BlendTypes.FXDIB_BLEND_MULTIPLY;
            }
        }
    }
    else
    {
        // --- DISABLE SIMULATION (RESTORE ORIGINALS) ---
        foreach (PdfPageObject pageObj in page.PageObjects)
        {
            // Only revert objects previously modified
            if (pageBackup.ContainsKey(pageObj.Handle))
            {
                BlendTypes originalBlend = pageBackup[pageObj.Handle];

                // Restore original blend mode
                pageObj.BlendMode = originalBlend;
            }
        }
    }
}