This is the largest known collection of Friedlander circus posters in the world. It doesn't come up in google searches all the time, and it's a great resource for circus-poster imagery. This collection was owned by the circus archiver Jaap Best. From the website:
"After Best’s death, Teyler Museum agreed to facilitate storage of the
archive and to open the collections to the public. At the same time, to
make the posters more generally available, Pictura was approached to
make digital photographs which could be posted online. The website
circusmuseum.nl was launched on 9 June 2005."
There are only a few tattoo posters in the archive, but it's wonderfull to see this vast slice of European circus history. And now, copies of the posters may be downloaded for research and educational purposes. I have seen MANY Friedlander poster copies for sale on etsy. Just know that those etsy shops do not possess the copyrights to those posters' images. And, you can purchase from this archive--I've not done so (yet), but I assume they'd ship to the U.S.