Starting with version 11 PhotoLine is offering a better compression of images. Furthermore it is possible to embed JPEG-files directly. Sadly older versions of PhotoLine are not able to read these new documents. Therefore Use old 32 bit Format can be used to disallow the new compression features.
Images without attached JPEG-data are saved as PNG images on saving using the PLD-format. PhotoLine is using the best compression in this case. But sometimes the best compression my be to time-consuming. Therefore you can reduce the level of compression or can turn off compression at all by using Image Compression.