Added support for mergeCells: // mergeCells (B2:G2), you may use CellHelper::getColumnLettersFromColumnIndex() to convert from "B2" to "[1,2]" $writer->mergeCells([1,2], [6, 2]); cell height: $row->setHeight(30); shouldShrinkToFit: $style->setShouldShrinkToFit(); These changes are implemented for XLSX as that's what I need and test spout on.