| Quarterly key indicators | Q1/2021 | Q4/2020 | Q3/2020 | Q2/2020 | Q1/2020 |
| Net sales, M€ | 6.2 | 5.9 | 5.9 | 7.1 | 6.7 |
| Operating result before depreciation (EBITDA), M€ | -0.1 | 0.4 | 0.5 | 0.6 | 0.0 |
| Operating result (EBIT), M€ | -0.5 | 0.0 | 0.1 | 0.3 | -0.4 |
| of net sales, % | -8% | -1% | 2% | 4% | -6% |
| Profit/loss before taxes, M€ | -0.5 | -0.2 | 0.0 | 0.2 | -0.4 |
| of net sales, % | -7% | -3% | 0% | 3% | -7% |
| Net profit/loss for the period, M€ | -0.5 | 0.1 | 0.0 | 0.2 | -0.4 |
| of net sales, % | -7% | 2% | 0% | 3% | -7% |
| Equity ratio, % | 63% | 64% | 63% | 62% | 64% |
| Gearing, % | 21% | 17% | 14% | 14% | 21% |
| Gross investments in fixed assets, M€ | 0.6 | 0.4 | 0.3 | 0.3 | 1.0 |
| of net sales, % | 10% | 6% | 6% | 5% | 14% |
| Personnel, end of the quarter | 134 | 138 | 142 | 144 | 139 |
| Earnings/share (EPS), € | -0.07 | 0.02 | 0.00 | 0.03 | -0.07 |
| Equity/share, € | 2.44 | 2.51 | 2.48 | 2.63 | 2.60 |