This is a good question, and a somewhat difficult one, because dishwasher detergent is really aggressive stuff.

I've had success with fine-tip permanent felt-tip pens, but not all brands will work, and you can't predict the outcome when you're shopping for pens.

A workable and non-destructive alternative is nail polish. You won't be able to write the exact volume on the scoop, but you can color-code them using a dot or two on the handle. It can chip away with time, but seeing that scoops are usually not in daily use, it may last long enough for your needs.

The really certain solutions would be etching or engraving. You could etch them yourself, if you're willing to work with a strong acid. If the handles are plastics, ask in an electronics shop for the stuff they etch PCBs with. If they're metal, you would need 25% HCl or something similarly strong, and you should be able to achieve a visible discoloration even on stainless steel. Again, nail polish can be useful here, in this case to apply the template for the etching (at least it works with the PCB flux, I don't know if it stands up to HCl).

As for engraving, I don't know of a way to do it at home - even if you had a tool for it, it would be difficult to actually write any kind of text without spending months of training. But since all you need is a way to differentiate only four items, you can just use a drill to make a distinctive pattern of a few holes in the handle. Or you can go to a professional to engrave numbers, especially if it's metal.

The last option I'd consider is to try super strong mounting glue like Sikaflex to add something visually distinctive, like a colored bead, to the handles, so it would look like color-coded fondue sticks. I haven't tried this in a dishwasher, but it really works as advertised in difficult environments.

If you have handles made from a known plastics, you can consider if it's suitable for plastics welding. You probably won't even need to weld anything to the handles, just use differently colored filament on each scoop.

This is a good question, and a somewhat difficult one, because dishwasher detergent is really aggressive stuff.

I've had success with fine-tip permanent felt-tip pens, but not all brands will work, and you can't predict the outcome when you're shopping for pens.

A workable and non-destructive alternative is nail polish. You won't be able to write the exact volume on the scoop, but you can color-code them using a dot or two on the handle. It can chip away with time, but seeing that scoops are usually not in daily use, it may last long enough for your needs.

The really certain solutions would be etching or engraving. You could etch them yourself, if you're willing to work with a strong acid. If the handles are plastics, ask in an electronics shop for the stuff they etch PCBs with. If they're metal, you would need 25% HCl or something similarly strong, and you should be able to achieve a visible discoloration even on stainless steel. Again, nail polish can be useful here, in this case to apply the template for the etching (at least it works with the PCB flux, I don't know if it stands up to HCl).

As for engraving, I don't know of a way to do it at home - even if you had a tool for it, it would be difficult to actually write any kind of text without spending months of training. But since all you need is a way to differentiate only four items, you can just use a drill to make a distinctive pattern of a few holes in the handle. Or you can go to a professional to engrave numbers, especially if it's metal.

The last option I'd consider is to try super strong mounting glue like Sikaflex to add something visually distinctive, like a colored bead, to the handles, so it would look like color-coded fondue sticks. I haven't tried this in a dishwasher, but it really works as advertised in difficult environments.

If you have handles made from a known plastics, you can consider if it's suitable for plastics welding. You probably won't even need to weld anything to the handles, just use differently colored filament on each scoop.

If you have the exact same model as shown in the picture, the easiest solution might be yarn. Crochet a tight ring of yarn between the handle and the guard to color-code the scoops, and it shouldn't slip away. If you can't crochet, you can also try winding it at that place tightly until you have a snug, nicely visible band of color.

This is a good question, and a somewhat difficult one, because dishwasher detergent is really aggressive stuff.

I've had success with fine-tip permanent felt-tip pens, but not all brands will work, and you can't predict the outcome when you're shopping for pens.

A workable and non-destructive alternative is nail polish. You won't be able to write the exact volume on the scoop, but you can color-code them using a dot or two on the handle. It can chip away with time, but seeing that scoops are usually not in daily use, it may last long enough for your needs.

The really certain solutions would be etching or engraving. You could etch them yourself, if you're willing to work with a strong acid. Maybe ask in an electronics shop for the stuff they etch PCBs with. Again, nail polish will be useful here, in that case to apply the template for the etching.

As for engraving, I don't know of a way to do it at home - even if you had a tool for it, it would be difficult to actually write any kind of text without spending months of training. But since all you need is a way to differentiate only four items, you can just use a drill to make a distinctive pattern of a few holes in the handle.

The last option I'd consider is to try super strong mounting glue like Sikaflex to add something visually distinctive, like a colored bead, to the handles, so it would look like color-coded fondue sticks. I haven't tried this in a dishwasher, but it really works as advertised in difficult environments.

If you have handles made from a known plastics, you can consider if it's suitable for plastics welding. You probably won't even need to weld anything to the handles, just use differently colored filament on each scoop.

This is a good question, and a somewhat difficult one, because dishwasher detergent is really aggressive stuff.

I've had success with fine-tip permanent felt-tip pens, but not all brands will work, and you can't predict the outcome when you're shopping for pens.

A workable and non-destructive alternative is nail polish. You won't be able to write the exact volume on the scoop, but you can color-code them using a dot or two on the handle. It can chip away with time, but seeing that scoops are usually not in daily use, it may last long enough for your needs.

The really certain solutions would be etching or engraving. You could etch them yourself, if you're willing to work with a strong acid. If the handles are plastics, ask in an electronics shop for the stuff they etch PCBs with. If they're metal, you would need 25% HCl or something similarly strong, and you should be able to achieve a visible discoloration even on stainless steel. Again, nail polish can be useful here, in this case to apply the template for the etching (at least it works with the PCB flux, I don't know if it stands up to HCl).

As for engraving, I don't know of a way to do it at home - even if you had a tool for it, it would be difficult to actually write any kind of text without spending months of training. But since all you need is a way to differentiate only four items, you can just use a drill to make a distinctive pattern of a few holes in the handle. Or you can go to a professional to engrave numbers, especially if it's metal.

The last option I'd consider is to try super strong mounting glue like Sikaflex to add something visually distinctive, like a colored bead, to the handles, so it would look like color-coded fondue sticks. I haven't tried this in a dishwasher, but it really works as advertised in difficult environments.

If you have handles made from a known plastics, you can consider if it's suitable for plastics welding. You probably won't even need to weld anything to the handles, just use differently colored filament on each scoop.