Add negative sign to the amounts in creditmemo pdf

You can add the negative signs by copying app/design/frontend/base/default/template/fooman/pdfcustomiser/creditmemo/bottom.phtml to your custom theme and prepend the negative sign before

$total['amount']
$total['base_amount']

You can apply the negative signs to the amount within the product columns in app/design/frontend/base/default/template/fooman/pdfcustomiser/item.phtml. For example, replace

        case 'subtotal':
            ?>
            <td style="<?php echo $style ?>" align="<?php echo $column['align'] ?>"
                width="<?php echo $column['width'] ?>%"><?php echo $vertSpacing .
                    $this->getPdfHelper()->OutputPrice(
                        $pdfItem['subtotal'],
                        $pdfItem['baseSubtotal'],
                        $this->getPdfHelper()->getDisplayBoth(),
                        $this->getPdfHelper()->getSalesObject()
                    ) . ($isNotLast ? '' : $vertSpacing) ?></td>
            <?php break;

with

        case 'subtotal':
            ?>
            <td style="<?php echo $style ?>" align="<?php echo $column['align'] ?>"
                width="<?php echo $column['width'] ?>%"><?php echo $vertSpacing ?>
                    <?php if ($this->getPdfHelper() instanceof Fooman_PdfCustomiser_Helper_Pdf_Creditmemo) : ?>
                        <?php echo $this->getPdfHelper()->OutputPrice(
                            -$pdfItem['subtotal'],
                            -$pdfItem['baseSubtotal'],
                            $this->getPdfHelper()->getDisplayBoth(),
                            $this->getPdfHelper()->getSalesObject()
                        ) ?>
                    <?php else : ?>
                        <?php echo $this->getPdfHelper()->OutputPrice(
                            $pdfItem['subtotal'],
                            $pdfItem['baseSubtotal'],
                            $this->getPdfHelper()->getDisplayBoth(),
                            $this->getPdfHelper()->getSalesObject()
                        ) ?>
                    <?php endif; ?>
                    <?php ($isNotLast ? '' : $vertSpacing) ?></td>