what did you glue the decal to? Some kind of clear plastic
T
I use plain printer paper in Word. I size the text and use Railroad Roman font on black background. I glue the label to a small piece of clear Styrene sheet and illuminate them with a warm white LED from the rear.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
My old Athearn BB models weren't worth that much trouble, but I printed up small white-on-black numbers, cut them to fit and glued them on. No illumination, but they look fine to me.
It takes an iron man to play with a toy iron horse.
Where possible I like to put a second LED behind the headlight LED and drive it off an auxiliary function. This allows me to keep the number boards lit with the headlight off.
BLI_BLE_RS15dcc by Edmund, on Flickr
IMG_8934_fix by Edmund, on Flickr
Microscale and probably others have number board decals that are made to be illuminated.
http://www.microscale.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=MD&Product_Code=87-205&Category_Code=NUM
I usually check the brightness of the LED and add resistance to make it dimmer than the headlight. Sometimes they are still too bright and I'll place either a piece of Kapton tape or a thin tape like the Tamiya masking tape which reduces glare and gives the number board a nice, yellowish glow.
BnO_E9-1456-2 by Edmund, on Flickr
Good Luck, Ed
What is the best way to create lite number boards on model locos?