Wapperdude's posts did indeed break the thread. I have no idea why. It's probably best to attach .zips, not raw .vsd files.
Anyway, I've deleted the 'offending' posts, then reposted below:
From Wapperdude:
But, if you change the pixels/in which defaults to 96 for png, to something like 960 or slightly smaller, then save as png, you will get better resolution than wmf at ~ the same file size. At least I did. My test included script font, 6pt, on 8.5x11 drawing page. All in English. I also include circular shape and an irregular shape with a variety of segments at different slopes, plus gradient files. PNG at higher pixel count was fine.
HTH
Wapperdude.
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From Wapperdude:
Well, looks like my last post is doing that mysterious here it is, here it isn't trick again. Must be the attachment.
Anyway, I re-did the original Visio, added both Hebrew and Chinese characters, and then saved as png file. The save settings had a resolution of 780pixels/in. The PNG file was quite clear and legible. Nothing seemed missing, and resolution for this test case was reasonable. If desired, I can add the Visio file tomorrow.
Wapperdude