We recently confirmed that Sony used a glass back cover for the Japanese Xperia Z1 f, whilst the global Xperia Z1 Compact used a plastic rear. This has led some users to take action into their own hands and replace their plastic back covers with the glass part from the Xperia Z1 f. This part can be bought from retailer Witrigs for less than $20 delivered. One advantage of changing the back cover is that users are reporting that it fixes the flash bleed problem. You will also notice that some have taken the opportunity to adopt a black rear even with coloured phones, which gives a nice effect. The only negative for some is that you have the SO-02F model number printed on the back (the model number of the Xperia Z1 f).