Quality of png-sequence

Hello to all
To generate fallbacks, I use png-sequence.
In example, I do the sequence to the timeline point I use the fallback and the last picture in the sequence is my fallback-image.
Unfortunately, the quality of this images is quite bad.
Is there a way to produce better fallbacks?
On the uploaded image you can see the html-version on the left and the fallback on the right.
Thanks very much for your help.
Best wishes, Urs

The PNG Sequence export does an export where the size is in pixel dimensions. Thus a 300x250 ad will get exported with 300x250 pixels. On a retina (2x) display the scene is actually showing at 600x500. Thus to get the same quality you’ll want to double the export size.

Sorry, I’m late! Thank you very much for your answer Jonathan.
I’m sure, you are right in what you’re saying.
When you are producing ads in the size of 300x250px, I’m not sure, that you’ll be allowed to deliver fallbacks in the double of size.
The next question would be, how are you producing the fallbacks in double of the size in hype?

When you export your sequence, double the width in the export screen and the height will automatically adjust:

If the ad network doesn't allow high resolution fallbacks they probably should... You may be able to deliver a 300x250 image with a DPI value of 216, but I think the whole point of fallbacks is that they have very low file sizes.

Oops, embarrassing! I realized the values more as info than as a possibility to change the size.
Thank you Daniel.