You begin with quite a good image that emphasises the strength of love. But the third line really puts me off. To me it doesn't contribute significantly to meaning and seems like it's just there for the sake of fulfilling the sonnet rhyme scheme. It's also too short a line to be in a sonnet.

This is something bad about writing sonnets and other closed-form poems. The rhyme scheme inhibits us in one way or another. We try to force things just for the sake of getting the format right. So this is something you'll have to beware when writing sonnets.

I didn't really like your use of elision in the fourth line either and am not sure why you had to cut short the word BENEATH because, if you didn't, you'd have kept to a perfect ten syllables, though of course the iambic rhythm is lost.

And in the sixth line I really feel that there should be no hyphen in between LONG and LOST.

On the plus side, I found the seventh line, which I think is where you depart from the initial progression of thought, quite interesting and well-written. I think you're saying that, as long as love is written about in poems and put on print, it will last forever. Is that it? Whatever it is, the seventh line is quite brilliant and the pure iambic rhythm adds to it too. Very good.

By the way there's a typo in the ninth line. You mean THY and THEY, don't you?

This poem is quite good. I was really impressed by the flow of the poem. The lines just seemed to mix together so well, mostly because the rhymes were well thought out. After reading it, i feel like the speaker is not just in love. I feel like he/she is totally head over heels for the person being described.

I thought that it was especially nice that you used many 'old english' words, such as thy and undimm'd. It's good that you used them sparingly, because sometimes having too much 'old english' makes people lose interest. Concerning the subject of the poem, i thought it odd that you would have 'a chain' as the description, when a chain is only mentioned in the first line of the poem. I did, however, like the direction that it went in. A love poem is always more appealing than a poem about a chain anyway.

In summary, you have done a really good job with Sonnet 3, but it would probably get more attention if it had a longer description.