How to Do Backfills and Fills for Gel French Manicures


There are two ways to rebalance French gels. One method involves carving out the free edge with an electric file and then applying new product. This method is called a backfill, and can be done with either a French fill diamond bit or a barrel-shape Swiss carbide bit.

Although these steps describe  removing pink-and-white enhancements, they can also be used for any type of gel enhancement with different colors on the free edges and nail beds, such as the reverse French or color tips.

Steps for a French backfill:

Step 1: Place the cutting edge of the bit on the nail plate just behind the smile line. With the machine on medium speed, gently carve a groove or trench into the product just behind where the free edge meets the nail. Be sure to keep the bit level and not to file all the way down to the natural nail.

Step 2: Keeping the bit parallel to the table, thin the white product on the free edge by about 80 to 90 percent. Be sure to lift the bit frequently to avoid heat buildup on the nail. If you can hear the speed of your machine slow as you file, increase the speed of the machine and reduce the downward pressure.

Step 3: Reduce the speed of the machine and refine the smile line until it’s smooth and even.

Step 4: Dehydrate the nail and apply new white product to the free edge. Cure under a UV lamp for about one minute to “freeze” it in place before applying any pink gel.

Step 5: File the pink gel in front of the growth area so it’s flush to the base of the natural nail, using care not to file into the natural nail. Keeping the bit parallel to the table, angle the client’s finger down toward the table to avoid creating rings of fire.

Step 6: Prep the new nail growth as you would for a regular fill. Apply pink gel to each nail as you would for a regular fill and cure. Be sure to follow the manufacturer’s instructions for the products you use.

Step 7: Apply shine or sealer and cure under a UV lamp if necessary.
The second method for rebalancing French gels is to reduce the product on the entire nail by about two-thirds, then apply white and pink as you would for a new set. This can be done with either an electric file or by hand, but I recommend using an electric file for the safest and fastest results.


Steps for a French fill:

Step 1: Using a coarse Swiss carbide bit (any shape) or a 100-grit abrasive board, reduce the product by about two-thirds.  

Step 2: Using a clean, fine-grit (220 or higher) abrasive board, prep the natural nail in the growth area between the cuticle and the old product; be careful not to damage the natural nail. Do not use electric files on the natural nail.

Step 3: Remove dust, then dehydrate and cleanse the nails.

Step 4: Apply white and pink product as you would when doing a new set of pink-and-white overlays. Be sure to follow the manufacturer’s application instructions for the products you use.

Step 5: Complete the service.

– Nancy King

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