Descriptions of Welsh costume
For an explanation of recording conventions, see Chronological survey.

Very little is known of the costumes worn by the women of Wales before about 1770. There are very few descriptions and illustrations of Welsh costume before that date, but the flood of visitors who came to experience the picturesque landscapes of Wales from 1770 recorded Welsh costume in much detail. Some of those who wrote about Wales before 1770 were very rude about the Welsh (e.g. Torbuck, below, although his description of wool gatherers might well be accurate.)

1722 Wrexham
I was there on a Market day and was particularly pleased to see the Welsh Ladies come to Market in their laced Hats, their own hair hanging round their Shoulders, and blue and scarlet cloaks like our Amazons.
[John Macky], A Journey Through England and Scotland, vol. 2, (which was added to the 2nd edition of the first volume), (1722), p. 132 and subsequent editions in 1724 and 1732.

This sentence was repeated in what purports to be the diary of George Boles or Bowles who lived at Mountprospect, County of Cork. During a leave of absence from the army in 1761-1762 he travelled home to Ireland via Chester and Holyhead. On his return journey he had to stop at Chester to await the ‘machine’ which took him back to London. The transcription of the diary includes the following:
1762, Chester
The next day being Saturday and market day I was particularly pleased to see the Welsh Ladies come into market in their laced hats, their hair hanging around their shouldiers [sic], and blue and scarlet clokes [sic] many of them with a Grey-hound in a string in their hands.
Bowles, George, Diary of Journeys between Ireland, and England 1761-1762, The Antiquary, vol. 36, (1900), pp. 369. The  transcription by George H. Green, MRIA, Dublin of the whole diary, covering four and a half months, was published over a period of months in the same volume,  pp.  203-206; 342-346 ; 366-370

There is no obvious explanation why this diary, which contains precise dates, personal and topographical details and costs, should include this and some other sentences from a book which went through several editions. In addition, it reversed the direction of travel (the original describes the route from Chester to Holyhead; when he came across the women in Chester, Bowles’ was travelling from Holyhead); he also transferred the women from Wrexham to Chester and added several errors of spelling.
The same sentence was repeated almost word for word in the following:
Martin, Benjamin, The natural history of England; or, a description of each particular county In regard to the curious Productions of Nature and Art…. vol. 2, (London, 1763), which includes an Introduction to the History of the Principality of Wales, p. 379  but he reversed the sequence of the colours of the cloaks as did:
Dalton, William Hugh, The New and Complete English Traveller: or a New and Historical Survey and Modern Descriptions of England and Wales (London, 1794), p. 487

Unlike many of the descriptions of Welsh costumes, this quotation has been repeated in several important modern publications, and in one it was wrongly ascribed to Shrewsbury.
Buck, Anne, Dress in eighteenth-century England, (B. T. Batsford Ltd., 1979), p. 150
Susan M. Johns, Gender, Nation and Conquest in the High Middle Ages: Nest of Deheubarth, (Manchester, 2013), p. 151

1730 Between Tregaron and Cardigan
Women wore neither Shoe nor Stockings: their Garments are full short; their upper Covering a dusky –coloured Stuff, over that Night-Rail of the same sort or sometimes of a red colour. A Piece of Black Gauze, or Crape (as I take it) in form of Skull-Cap comes over the head and is pinned close under the chin; over this a Man’s Hat lopped.
Loveday, John, (1711-1789). Markham, Sarah, John Loveday of Caversham, 1711-1789: The life and tours of an eighteenth century onlooker. (Wilton: Russell, 1984) p. 62

1732 Holyhead
Some of the ordinary Women in N. Wales wear Stockings without feet and no Shoes: so do several boys. The Women all wear black Hats … in the other parts of their dress, much superior to the Sex in S. Wales
Loveday, John, (1711-1789) Diary of a tour in 1732 through parts of England, Wales, Ireland and Scotland, … Printed from a manuscript in the possession of his great-grandson J. E. T. Loveday, with an introduction and an itinerary. Edinburgh: 1890 (W. Blackwood and Sons), p. 122

The Briton Described, wool gatherers
We met a Crew of these Pickering Wool- gatherers, the very Emblems of Beggary, and but once removed from vilest Rascality; one Shoe a-piece, and half a Hat, a. Remnant of a Doublet, and a Moiety of a Sleeve, a Pair of Dispocket Breeches, and a jagged Jump, were the Flower of their Accoutrements, except two or three Locks of Wool tuck’d like Scuts under their Girdles as a Badge of their Profession; and some cramm’d Stockings bobbing at their Sides as Trophies of their Pyracies.
Torbuck, J.T., (editor), A collection of Welch travels and memoirs of Wales. (London, 1742), p. 30

about 1747
I will spin our wool and make stockings for Morgan [her son] and myself, and the weaver shall weave us a piece of Tilsy-wolsy [Linsey woolsey?] every year, and the tailor shall make Morgan a suit of clothes and me a gown, and we will sow our own flax and I will spin that into [linen] shirts, shifts and sheets, and we will live so well and go so fine as we can.
Broadsheet about a woman and her husband going to London. ‘Unnafred Shones, wife to Shon ap Morgan’, published by William Dicey, London, c 1747

24.6.1748 Middlesex
The Swede Pehr Kalm described Welsh female season workers: ‘women and girls, mostly, from Wales, all in good clothes, very clean and tidy.’
Kalm, Pehr, Resejournal over Resan till Norra Maerika in Skrifter Svenska Litteratursällskapet i Finland, Rhif 419, tt. 355-356, Copenhagen, 1966. Translated into Welsh from Swedish by Linnard, in Merched y Gerddi yn Llundain ac yng Nghymru, Ceredigion, (1982), pp. 260-263

1755 [Wales]
The peasants wear no shoes about their houses, and in their common travelling the roads, they carry them in their hands, and wash their feet near the towns which they are travelling to, when they put on them and their stockings; many of them, however, have none. And yet these poor creatures would think themselves deemed to perpetual slavery if they were obliged to wear wooden shoes; the ideas of wooden shoes, slavery, and French being all linked together in their imaginations; they would scarce prefer them to confinement without and as soon wear chains as preserve their feet from injury by these contrivances; the flattering idea of being free, though bare-footed, gives no little consolation amidst as much slavery as poverty and dependence can bequeath …
Angeloni, Battista (J. Shebbeare?), Letters on the English Nation (1755) (see A Jesuit’s Description of Wales, Wales, I, 1894, 299-301)

1766 St Asaph
‘The inn is good and clean and the landlady has a pretty daughter who was fitted out most amazingly. … All through Wales … the women and girls are exceedingly handsome, their complexion at least exquisite, to which the constant wear of a hat [sic], no doubt greatly contributes.’
Beaufort, Daniel Augustus, Rev (1739-1821), Trinity College, Dublin, MS4024-6; Ellison, C.C., The Hopeful Traveller (1987); McGarvie, M., An Irishman in Wales: Daniel Beaufort’s Journals for 1766 and 1779, [Transcription with commentary] Transactions of the Ancient Monument Society 29 (1985), p. 92