As you know , a lens is a filter which change the blur or sharpness of a point with its place on the lens and with its color.
How can I change the sharpness of a drop at printer ?
As you know printers jet the dots on to the paper with the shape of spheres.
These spheres take a half dome shape on the paper and evoprates quickly.
If we can change this domes sharpness , we can change the appearance of the picture.
I think this is possible with varying the speed of printer head .For that time , first time , it is possible to say that hp printing head is more favor to this job because it is easier to change the dot heat than to change piezo speed.
Best ,
Mustafa Umut Sarac