Cross stitch is possibly the "youngest" of all Ukrainian embroidery seams, it's not traditional, as it came to us in a late XIX century only. There was a French Brocard company which sold a cheap glycerine soap, and they added an embroidery schema to every piece as a nice marketing trick. There were roses, birds, grapes, berries and other stuff, and they became insanely popular. Cross stitch allowed to fill in a large areas relatively fast.
Also, many traditional Ukrainian embroidery patterns could be transitioned into cross stitch smoothly. That's what many Ukrainian ladies did.
I'd dare to say that the majority of embroidered shirts existing are done in cross stitch, as a lot of older pieces were lost or are in a poor state.
(source with video tutorial)
Cross stitch was used in Ukrainian embroidery long before XIX century, but it was used for only a certain parts of the embroidery, like in this shirt, where cross stitch is used only on the cuffs:
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The same here, only on the collar:
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Also double cross stitch was used:
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Here are some patterns from Brocard:
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And some traditional Ukrainian patterns:
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As cross stitch is great for machine embroidery, our market is filled with all kinds of clothes adorned with patterns in Ukrainian style:
(these are sold fast, here is the source of our online market of new and used clothes)
To be continued...