The path is to start at the North Cape in Norway and to end in southern Italy. Currently it is marked for 4.900km. Thereof are 1.900 km inside Germany; from the Danish border near Flensburg to the Swiss border at Konstanz / Lake Constance. A good first overview can be found on the website of the European Ramblers Associations.
Recently the European walking associations have agreed on the following marker. It is to be used in addition to local markers.
I have walked so far the section from middle of Sweden through Denmark Germany and Switzerland at the Italian Border.
In Sweden it starts at Grövelsjön which is located near the Norwegian border and ends in Varberg, the ferry port for Denmark. The path is split into various Swedish walking trails. However it is marked continuously in red or orange. Additionally there are separate signs for each path. Starting at Varberg these are Hallandsleden, Bohusleden, Vildmarksleden, Knalleleden, Sjuhäradsleden, Redwägsleden, Västra Vätterleden, Bergslagsleden, Malingsbo - Kloten Rundan, Smeleden, Gagnefs Pasture Path, Siljansleden, Vasaloppsleden and Södra Kungsleden.
In Denmark the E1 starts at Grenaa as Molsruten. It continues from Århus to Silkeborg. Following a short connecting path it uses parts of the Naturstien Horsens - Silkeborg along a former railroad track. Another short connecting path and the main section along the Hærvejen up to Flensburg is reached.
There is a printable flyer covering the Molsruten with detailed map available on the Internet. And this is the path marking:
The same is available for the section from Århus to Silkeborg. Here the walker without additional text is used.
The path Naturstien Horsens - Silkeborg wis also known as Bryrup banestien. A printable flyer is available too. This is the marking:
The Hærvejen website provides very detailed printable path maps. This walker with the additional text Hærvejen is used as path marking:
In Germany I have so far completed the section from Flensburg to Celle. From Flensburg until Ratzeburg it can be covered from youth hostel to youth hostel.
Until now the St. Andrews cross is the marker for European paths in Germany. However it is not uniformly applied. So far with very few exceptions it is well marked.
In Black Forest and onwards to Constance the trail is maintained by the hiking club Schwarzwaldverein. They have their own markings and don't care about what is done along the rest of the E1 in Germany. There is very little information that this is part of the European E1. Until Mountain Feldberg the trail is marked as Westweg with the following sign:
From Mountain Feldberg until Constance the trail is marked as "Querweg Freiburg - Lake Constance" with this sign:
In Schleswig-Holstein there is an alternative named E1a. It is also known as Schlei-Eider-Elbe path. It starts in Schleswig and runs towards Heide and then across the Kiel Channel to Itzehoe and finally meeting the E9 at Vossloch. From here to Hamburg-Blankenese both paths are together. In Hamburg-Blankenese it ends and continues as E1. The E1a lacks at various parts a sufficient marking. Here a map is a must.
In Switzerland the E1 is well marked along it's total length. Depending on whether a stretch is considered to be alpine or not one of two possible markings is applied. The non alpine sections are marked with a yellow sign; the mountainous once are marked with white-red-white stripes. Additionally there are signs with mileage and in the mountains even with travel times.
My tour guide as well as map is the "Kompass Wanderführer 1057 Europäischer Fernwanderweg E1" in German language. So far I have not missed standard walking maps with a scale of 1:50.000. The maps included in the guide as well as the markings found along the path have been sufficient. Since Celle I am using the software Backcountry Navigator on my smart phone. I have downloaded the respective maps and the GPS-track.