This little catalog was stamped with the name of Charles Altemus, the owner of The Opera House Hat Store in Easton, Pennsylvania which he owned from around 1896 until he went bankrupt in February of 1912.
The Opera House Hat store was a fancy haberdashery selling fine menswear especially hats. It was a thriving business as early as 1872 when it was known as Ramaley’s Opera House Hat Store, (owned and founded by Mr. Ramaley) primarily in making and selling men’s hats and fur goods. Sometime around 1896 the business passed to Mr Altemus who branched out into other men’s furnishings including collars. This catalog therefore definitively is from sometime between 1896-1912.
However, the catalog may be able to date to a smaller window of time by comparing the prices and names of the collars to newspaper ads of the collars in it. Newspaper ads typically only advertise collars heavily within their first year of launch, while long popular collars stay in catalogs as long as people buy them. This 1900 newspaper clipping below has names of quite a few of the same collars as this catalog, and you can see the ad at this link:
Wed, Aug 22, 1900 – 6 · The Troy Messenger (Troy, Alabama) · Newspapers.com
Three other Ads from 1902 and 1903 have more of the collars from the catalog, as well as a similar style in the artwork, so 1903 is (so far) the more precise date I would guess this catalog is from:
It also has a similar style to the side-images in the memorable Glencoe Collar as a Postcard from the Philippine Front ad in the December 1902 Pearson’s Magazine. [On a side note, I recently obtained a detachable cuff that had been used this way and sent from Oklahoma to Missouri in 1908!].
However there is an equally good argument for 1905 as the date, as there is an ad that mentions more of the collars from the catalog, although it is primarily pushing the “Four Ply Fold” feature rather than “New” collars:
Comparing the central “Correct Dress Chart” with similar charts in The Haberdasher, The Sartorial Art Journal, etc. would most likely give a definitive year so if anyone cares to go to the Library of Congress to check for me, I’ll be happy to alter my judgement on this if I get further info!