Hi there! Because the forum you originally posted in is for beginners trying to learn the basics of Photoshop, I moved your question to the Photoshop Elements forum, where you'll get more specialized help.
Simply add your scanned image to the preset manager.
You can then add into your designs as a fill layer (pattern).
You can follow this steps to achieve what you want
1. Open your scanned images in Editor.
2. Now choose "Edit Menu>Define Pattern". This will save your image as a pattern.
3. To permanently save this pattern , open "Edit>Preset Manager>Patterns"
4. Select the pattern you just created in step 2.
5. Choose "Save Set" and save it with some name say "X".
6. Close and Relaunch PSE and the pattern preset file "X" containing your pattern will be loaded and you can use if forever now.
Do reply if you any questions.
Do you have the cloth ( fabric) so that you could photograph rather than scan it?