Step 1: The Problem: 50+ letters to send
In addition I had to to put not adhesive stamps on every letter. I had adhesive stamps but they were valid only for standard letters and mine got heavy so I had to put some extra postage on. And those extra postage stamps had also to be moistened to become adhesive.
So I came up with this little helper made entirely form household materials: A small peace of sponge squeezed into a clothespin.
The sponge will hold the water for moistening and the clothespin will act as a shaft to hold it without getting wet fingers (and therefor spoiling the envelopes).
Step 2: Gather Materials
To build this little helper you 'll need a scissor or some (kind of x-acto) knife/cutter. The knife works better since the scissors will squeeze the sponge more then it will cut through it. I started with a scissor but change to a (sharp kitchen) knife.
A non permanent marker will also be handy.
Step 3: Mark and Cut
To mark this cutout volume hold your clothespin on top of the sponge and mark the width of the clothespin.
The length and depth of the cutout depend also on your clothespin. Just remember you only need a little tip.
Then cut out the volume along the marked lines.
If there are leftovers from the marker on the cutout then wash it to get rid of it. Otherwise you'll spoil the envelopes later.